ABC TECHNOLOGIES. Forensic Science II. SAMPLE PAGES Not for Duplication. by Greg and Carolyn Ulmer

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1 ABC TECHNOLOGIES Forensic Science II by Greg and Carolyn Ulmer Copyright 2009, Greg and Carolyn Ulmer, All Rights Reserved

2 CONTENTS Disclaimer/Acknowledgments, 1 Teacher Instructions for ABC Technologies, 2-10 Reference Materials For Students, ABC Technologies Materials *Training Lab - Blood As Evidence-Blood Drops Dripping From A Wound* Training Lab, 22 Teacher Notes, 30 Questions, 26 Key, 33 *Training Lab Blood As Evidence-Blood Drops Falling At An Angle* Training Lab, 37 Teacher Notes, 47 Questions, 45 Key, 51 *Training Lab Blood As Evidence-Analyzing Blood Spatters* Training Lab, 53 Teacher Notes, 62 Questions, 59 Key, 64 *Job Nashville Police Blood Spatter* Letter, 67 Teacher Script, 78 Memo, 68 Key to Crime, 80 Teacher Notes, 74 *Reference Page Firearms And Ballistics-Part 1: Bullets and Barrels* Reference Page, 82 Questions, 85 Key, 87 *Training Lab Firearms And Ballistics: Barrel and Bullet Striations* Training Lab, 89 Teacher Notes, 97 Questions, 96 Key, 98 *Reference Page Firearms And Ballistics-Part 2: Cartridges* Reference Page, 99 Questions, 103 Key, 106 *Training Lab Firearms and Ballistics: How To Determine A Bullet s Trajectory* Training Lab, 109 Teacher Notes, 116 Data Page And Questions, 113 Key, 119 *Training Lab Firearms and Ballistics: Using Bullet Trajectory To Determine The Position Of A Close Range Shooter* Training Lab, 122 Teacher Notes, 128 Questions, 127 Key, 131

3 *Training Lab Firearms And Ballistics: Using Bullet Trajectory To Determine The Position of a Distant Shooter* Training Lab, 132 Teacher Notes, 140 Questions, 138 Key, 144 *Job The Case Of Shattered Dreams* Memo, 146 Evaluation Page, 167 Crime Scene Evidence, 151 Teacher Notes, 168 Police Report Form, 162 Key 170 *Proficiency Quiz* Quiz, 177 Teacher Notes, 183 Key, 184 *Reference Page Glass As Evidence* Reference Page, 188 Teacher Notes, 196 Questions, 191 Key, 198 *Training Lab Glass As Evidence: Density And Refractive Index* Training Lab, 202 Questions, 208 Teacher Notes, 211 Key, 217 *Reference Page/Training Lab Soil As Evidence* Reference Page/Train Lab, 220 Teacher Notes, 232 Questions, 229 Key, 239 *Reference Page/Training Lab Plant Pollen As Evidence* Reference Page/Train Lab, 242 Teacher Notes, 256 Questions, 254 Key, 260 *Job Evergreen Sheriff Pollen Evidence* Letter, 262 Evaluation Page, 265 Memo, 263 Teacher Notes, 266 Client Responses, 264 *Training Lab Improving Your Observation And Memory Skills* Training Lab, 269 Teacher Notes, 276 Key, 279 *Job Constructing A Suspect s Composite Face* Memo, 281 Evaluation Page, 283 Questioning A Witness, 282 Teacher Notes, 284

4 *Training Lab Forensics Chemistry: Identifying White Powder* Training Lab, 288 Teacher Notes, 296 Questions, 294 Key, 300 *Job Forensic Chemistry Challenge* Chemistry Challenge, 302 Teacher Notes, 305 Evaluation Page, 304 Key, 307 *Reference Page/Training Lab Forensic Chemistry: Identifying Chemicals With Spectrophotometry* Reference Page/Train Lab, 308 Contract, 321 Questions, 316 Teacher Notes, 322 Data Tables and Graph, 318 Key, 329 *Job Puppy Love Veterinary Clinic* Letter, 331 Client Responses, 335 Memo, 332 Evaluation Page, 336 Table and Graph, 333 Teacher Notes, 337 *Training Lab Skeletal Remains: Identifying Bones* Training Lab, 342 Questions, 350 Teacher Notes, 352 Key, 355 *Training Lab Skeletal Remains: Determining A Victim s Height* Training Lab, 357 Questions, 362 Teacher Notes, 363 Key, 366 *Training Lab Skeletal Remains: Determining A Victim s Sex* Training Lab, 367 Questions, 377 Teacher Notes, 379 Key, 387 *Training Lab Skeletal Remains: Determining A Victim s Age* Training Lab, 389 Teacher Notes, 399 *Job Skeletal Remains Discovered At School* Letter, 410 Evaluation Page, 414 Memo, 411 Teacher Notes, 415 Organizing Your Analysis, 412 Key, 419 Skeletal Remains ID Form, 413 *Reference Page Estimating Time of Death* Reference Page, 420 Teacher Notes, 427 Questions, 424 Key, 428

5 *Job The Square Root Kidnapper Crime* Crime Introduction, 431 Detailed Teacher Notes, 432 Setting Up The Crime Scene, 439 How To Prepare The Evidence To Hand Out To Students To Analyze, 447 Preparing The Map That Leads To Sammy s Location, 458 Preparing The Clues That Lead To The Map s Location, 460 Preparing The Six Forensic Challenges, 462 Preparing Sammy To Be Kidnapped, 472 Student Pages To Hand Out, 472 Official Police Report, 473 Memo, 474 Student Investigator Forms, 475 The Evidence Never Lies Form, 478 Evaluation Page, 479 Final Teacher Checklist, 480 Summary Of Forensic Challenges, 481 Day-By-Day Summary Of How To Run The Crime, 482 Key, 485 *Proficiency Quiz* Quiz, 490 Key, 496 Materials List For ABC Technologies Equipment and Supplies Needed, 498

6 ABC Technologies Materials 21

7 TRAINING LAB BLOOD AS EVIDENCE BLOOD DROPS DRIPPING FROM A WOUND NAME Background: Blood drops at a crime scene, called BLOOD SPATTER, can be important clues to help you recreate how the crime occurred. The shape of the blood drops can help you determine the location of the victim when they were injured, how an injured person moved about a crime scene, and even the method used to injure a victim. In this Training Lab you will be investigating blood that is dripping from a stationary (non-moving) victim. Blood drops dripping in this way are called PASSIVE BLOOD DROPS because they drop straight down with no outside forces pushing on them (and making them fall at an angle). 1. You will be trained to analyze passive blood drops to determine the height from which the blood drops fell. Procedures: Part 1 Collecting Blood Drops That Have Fallen From Different Heights 1. You will need a clipboard, SEVEN large note cards, a covered beaker of simulated blood, a dropper, an eight foot piece of string or cord, a meter stick, a roll of masking tape, and old newspaper to spread on the floor. 2. Tie a knot very close to one end of the string. Accurately measure 1 foot up from the knot at the end of the string and place a small piece of masking tape at this location (fold the tape over so it wraps around the string and sticks to itself forming a flag-like tab). Label this piece of tape 1foot. 3. Accurately measure 2 feet up from the knot at the end of the string and add another tab of tape. Label this piece of tape 2 feet. tape tab string 4. Repeat measuring, placing, and labeling tape tabs at 3 feet, 4 feet, 5 feet, 6 feet, and 7 feet up from the knot you placed at the end of the string. These tape tabs will represent the different heights from which you will release and observe blood drops. 5. Place your clipboard on the floor on top of newspaper (to protect the floor from any mess). Write your name and 1 foot in a corner of one of the large note cards (use a blank side of the note card). Place the labeled card on the clipboard (blank side up). You do not need to clip the card to the clipboard. 6. Clip the knot you placed at the end of the string just under the clip of the clipboard so it will be held in place. Stretch out the string above the clipboard and note card (see sketch at right). 7. Suck up simulated blood into the dropper (avoid sucking up bubbles). 8. Hold the OPEN END of the dropper EXACTLY 1 foot above the note card (even with the 1 foot tape tab on the string). Gently squeeze the dropper to release THREE separate drops of blood from 1 foot each drop falling on a different location of the card (the drops should not touch or overlap). You should NOT allow bubbles to form as you release drops. Add additional drops if any bubbles are present, or any drops overlap. string 22

8 9. Carefully remove the note card with blood drops (be careful and don t tilt the card or your blood drops will run and change shape). Place the card with wet blood drops on a flat surface where they can dry without being disturbed. 10. Repeat Steps #5 - #8 and collect THREE separate drops of blood from each of the remaining heights of 2 feet, 3 feet, 4 feet, 5 feet, 6 feet, and 7 feet. The blood dropped from each height should be collected on separate, labeled note cards. For the higher heights you may need to stand on a chair be careful! 14. After the blood drops are dry you can make observations and measurements. Part 2 Analyzing Blood Drops That Have Fallen From Different Heights 1. Observe the shapes of the blood drops on your cards. Because the drops fell straight down to the ground they should be a round shape as if dripping from a victim that was standing still. Blood drops that strike a surface at an angle (blood drops that are flung from a victim or drip from a moving victim) are more oval-shaped. 2. Look around the edges of your blood drops. You may notice that the blood drop edges are smooth, or there may be some jagged, pointy areas along the edges. Satellites These jagged, pointy areas are called SPIKES. Blood drops that fall on smooth, hard surfaces, like glass or tile, have smooth edges with few spikes. Blood drops that fall on a rough, fiber surface, like wood or paper, usually have jagged edges with more spikes. Blood 3. You may also notice smaller, separate specks of blood surrounding Drop some of your drops. These small specks are called SATELLITES and are sometimes thrown out of the large blood drop during impact with a hard surface. Spikes 4. Accurately measure the DIAMETER (in millimeters to the nearest 0.5mm) of each of the three blood drops you dropped from 1 foot. DO NOT include spikes or satellites in your diameter measurements. Record these measurements in Table 1 Blood Drop Diameters From Different Heights. 5. Repeat Step #4 by measuring and recording (in Table 1) the diameters (in millimeters to the nearest 0.5mm) of the blood drops you released from each height. 6. Calculate and record (in Table 1) the Average Blood Drop Diameter for each height. 7. Pick up Figure 1 Standard Curve For Diameter Of Passive Blood Drop vs. Height Blood Drop Fell from your supervisor. This graph already has points and a line on it, however, you should plot your AVERAGE Blood Drop Diameter for each height on this same graph. However, DO NOT draw a line through your points. Part 3 How To Use The Blood Drop Diameter vs. Height Graph 1. The graph in Figure 1(Diameter of Blood Drop vs. Height of Blood Drop) is an important tool. The graph contains a line called a STANDARD CURVE for Blood Drop Diameter vs. Blood Drop Height, and it can help you analyze blood spatter at a crime scene. Example - Pretend you are working a crime scene and the only evidence you find is a single, round blood drop on the floor. 1 st - Measure the diameter of the blood drop (to the nearest 0.5 millimeter). 2 nd - Find this diameter along the Y axis of the Blood Drop Diameter vs. Blood Drop Height graph and place your finger on this point. 23

9 3 rd - Next, move your finger straight and level across the graph (toward the right) to the Standard Curve and stop when you touch the line. 4 th - Next, move your finger straight down from the Standard Curve to the X axis and stop when you reach the axis. 5 th - What Height Value along the X axis is your finger touching? You will need to accurately estimate the Height Value if your finger is between two values. 6 th - The Height Value you determine from the X axis is the approximate height the blood drop fell before hitting the floor. This can tell you the approximate location of a bleeding person s injury even if the injured person is no longer present! 2. Look closely at your average blood drop diameters you plotted on the graph. Imagine what a best fit curve through your points would look like (imagine it don t actually draw one). This line would be a Standard Curve for Blood Drop Diameter vs. Blood Drop Height based on your measurements. It should look like the Standard Curve already drawn in but don t be disappointed if it doesn t. Your data was based on only three blood drops for each height. The Standard Curve on the graph was made by averaging the diameters of many blood drops therefore, it should be a little more accurate. Height of Blood Drop Table 1 Blood drop diameters from different heights 1 foot 2 feet 3 feet 4 feet 5 feet 6 feet 7 feet Trial # Diameter of Blood Drop (mm) 24 Average Diameter of Blood Drop (mm)

10 Diameter of the ROUND Passive Blood Drop (mm) Figure 1 - STANDARD CURVE FOR DIAMETER OF PASSIVE BLOOD DROP vs. HEIGHT BLOOD DROP FELL 1 foot 2 foot 3 foot 4 foot 5 foot 6 foot 7 foot 8 foot Height of the PASSIVE Blood Drop (feet) 25

11 QUESTIONS BLOOD AS EVIDENCE BLOOD DROPS DRIPPING FROM A WOUND NAME 1. Observe the blood drop points you plotted on the Blood Drop Diameter vs. Blood Drop Height graph and finish the following statement. My blood drop points would produce a Standard Curve that is (choose one): almost exactly like the Standard Curve that is already on the graph. somewhat similar to the Standard Curve that is already on the graph. not much like the Standard Curve that is already on the graph. 2. How can you look at a blood drop and determine if it dripped straight down from a wound or hit the floor at an angle (from a bleeding person that was running)? 3. How does a blood drop that falls on glass appear different from a blood drop that falls on a piece of paper? 4. You are looking at a blood drop from a crime scene that has a diameter of 16.5 mm. From approximately what height did this blood drop fall? THE CASE OF THE PARKING LOT MURDER You are investigating a murder that occurred approximately four hours earlier in the day. A witness saw two men arguing in a parking lot. She did not recognize either of the men, but described them both as being about 6 feet tall. The witness saw one man pull out a knife and swing it several times at the other man. The attacked man took a few steps back and stood for several seconds as he looked at his wounds which appeared to be bleeding. He then pulled out a gun, shot the man that was holding the knife, and ran from the scene. The man that was shot died of his wounds, and you are now on a search for the missing suspect. You find blood drops on the parking lot where the shooter stood and bled from his knife wounds. These exact same blood drops are visible on the next page, ready for your analysis (carefully measure blood drop diameter to the nearest 0.5mm). You decide to call area hospitals and see if anyone recently checked themselves in for treatment of lacerations (cuts). You discover that FIVE people recently checked in for laceration injuries: Patient A cut on the right calf (below the knee) Patient B cut left calf (below the knee) and left cheek Patient C cut along right hip region (just below waist) Patient D cut along left hip region (just below waist) and right cheek Patient E cut on left shoulder and forehead 26

12 #2 #5 #1 #3 #4 Complete the Blood Drop Evidence Form below and then answer the questions that follow about the crime. Evidence # Location of Blood Drop Diameter of Blood Drop (mm) Approximate Height Blood Drop Fell BLOOD DROP EVIDENCE FORM Parking Lot Parking Lot Parking Lot Parking Lot Parking Lot 5. In your opinion, did all the evidence blood drops fall from the same height? If you answered YES for Question #5 from approximately what height did all the blood drops fall? If you answered NO for Question #5 from how many different heights do you think the blood drops fell? 6. Based on the height(s) the evidence blood drops fell - list the body area (or body areas) where you think the suspect was injured by the knife. 7. Based on the blood drop evidence you analyzed, which patient is most likely your suspect? 27

13 THE CASE OF THE BLOODY KNEE You have been called to investigate a robbery at a local business. A single employee was working at the time. The employee stated that two men entered the business. One of the men quickly pulled a 2-foot tall stepladder (used to reach items on the store s top shelf) to the corner of the store near the door. The man stood on top of the stepladder, and pulled a plug on a security camera located there presumably so they could not be filmed. The man jumped down, picked up the ladder, then threw it across the store at the employee and demanded money. The employee was scared and gave the men all the cash that was in the register - $2,500. The men quickly left with the money and the employee immediately called the police. You notice several fresh drops of blood on the floor - three blood drops next to the cash register and four drops in the corner of the store beneath the disabled security camera near the door. These exact same blood drops are visible below, ready for your analysis (carefully measure blood drop diameter to the nearest 0.5mm). The employee states that all the blood drops came from a cut on her knee. She shows you the fresh cut on her knee and explains that the stepladder has a sharp edge and as the thrown ladder bounced across the floor it hit her knee and cut it. She says the drops by the cash register must have fallen while she removed the money, and the drops by the camera must have fallen as she stood near the door waiting for the police to arrive. You ask the employee how tall she is she looks a little confused, but answers 5 foot 6 inches tall. #1 #2 #4 #5 #3 #7 #6 Blood Drops By Cash Register Blood Drops Beneath Security Camera and Near Door 28

14 Complete the Blood Drop Evidence Form below and then answer the questions that follow about the crime. Evidence # BLOOD DROP EVIDENCE FORM Location of Blood Drop Diameter of Blood Drop (mm) Approximate Height Blood Drop Fell 8. Do all the evidence blood drops by the cash register appear to have fallen from the same height? 9. Which evidence blood drops by the cash register could have fallen from the employee s knee as stated? 10. Do all the evidence blood drops by the security camera and door appear to have fallen from the same height? 11. Which evidence blood drops by the security camera and door could have fallen from the employee s knee as stated? 12. A blood test completed back at the lab confirms that all the evidence blood drops belong to the employee. Soon after you complete your analysis of the blood drops you file a report to have the employee arrested for faking a robbery and stealing the $2,500 from the cash register. The employee later admitted her guilt, stating that she had worked alone to steal the money and made the robbery story up. Everyone in the crime lab is amazed that you solved this crime based on only a few drops of blood. Recreate (describe) the events you think happened as the employee stole the money including your conclusions about each of the evidence blood drops. 29

15 TEACHER NOTES Lab/Activity: Training Lab Blood As Evidence Blood Drops Dripping From A Wound Equipment To Prepare: 1 clipboard/group 7 5 x 8 white note cards/group the cards can be blank on both sides or just one side 8 feet of cotton twine, string, or thin cord/group for students to use as a measuring device 1 roll masking tape/group to place at 1 foot intervals along the string 1 meter stick/yard stick that measures in inches/group to measure out 1 foot intervals a small cup or beaker with cover/group to hold the simulated blood. Add only 10 to 15ml of simulated blood to the small cup/beaker. Cover the container with aluminum foil or similar to keep the blood from drying out throughout the day. 1 disposable, plastic dropper pipette (or similar)/group to drop blood drops old newspapers to cover the floor where students will be dropping blood. This will help prevent any messes. small millimeter ruler (clear works best)/group for students to measure their blood drops you will also need to find a place for students to place their cards while their blood drops dry (it may take several hours for the drops to dry). Have each group carefully overlap their cards as much as possible (without damaging their wet blood drops) to help save on space. When dry, you can stack them up Solutions To Prepare: Simulated Blood you will use about 40 to 50ml of simulated blood/class (each group will only use 2 to 3ml of simulated blood) however, you should make about 150ml of simulated blood and give each group 10 to 15ml (it is easier for students to suck up blood in their pipettes without getting bubbles if they have a larger volume of blood to work with). We purchase our simulated blood around Halloween from Walmart in the Halloween section (you can buy 1 pint/473ml of simulated blood for just a few dollars and it works great). Some simulated bloods will be thicker than others and give slightly different results when completing this Training Lab. We prefer to use slightly thinner blood than what is purchased, so we thin the purchased blood by mixing 20ml of water to every 30ml of purchased, simulated blood (2 water to every 3 blood). This makes the simulated blood last longer and slightly increases the diameter of the blood drops. You can store the diluted blood in a sealed container with no problems. To be consistent from year to year we check our simulated blood by dropping several drops on a note card from 6 feet high. The diameter most drops from this height should be around 19mm to 20mm. If the drops are too small we add a little more water to the simulated blood. Use this simple test if you want to end up with results similar to what we get. 30

16 There are several sources for simulated blood. You can purchase simulated blood from Biological Supply Companies (such as Wards Biological #37W5310), you can purchase Theatrical simulated blood through your Theatre Department (or Internet), you can purchase simulated blood from local stores (like Walmart, Kmart, Target, etc.) around Halloween which is where we get our simulated blood, you can often purchase simulated blood year-round from specialty stores that sell costumes and party supplies, or you can make your own simulated blood (there are many recipes on the Internet). As mentioned several times we always purchase our blood around Halloween in pint containers from Walmart. However, below is a recipe for making blood that seems to work fairly well. We ve never used it in class, but have tried it out ourselves (although we still prefer Walmart blood): 3 Tablespoons of clear corn syrup 2 ½ Tablespoons of water ½ teaspoon of powdered cocoa red food coloring to taste 1 drop of blue or green food coloring can also be added to darken color add more water if it is still too thick This blood recipe can t be stored for too long as fungus will begin to grow on it. This also produces a blood that can be a little sticky (from the syrup). Comments/Problems: This Training Lab usually takes 2 days to complete (Day 1 to make blood drops with time to spare, Day 2 to measure drops and answer Questions). Some students may need help using the dropper pipette to produce blood drops without air bubbles. The first drop released from the dropper pipette often has an air bubble in it. This lab was designed to use English units for height (since most students are more familiar with human heights measured in feet and inches). You can have students convert all height measurements to metric if you prefer. Use the approximate conversion 1 foot = 30.5 cm. Students should NOT produce their own Standard Curve from their blood drop results. Students will only compare the blood drop diameter versus blood drop height results they obtained to the supplied Standard Curve results. Students should use this supplied Standard Curve to answer all the Training Lab Questions. The Standard Curve used in this lab is not an official Standard Curve for Blood Drop Diameter vs. Blood Drop Height. It was constructed using the average of 20 blood drop diameters for each height (using Walmart simulated blood that was diluted 2 water for every 3 blood). 31

17 The results of this Training Lab can be variable usually based on the simulated blood your students use. Thicker simulated blood will produce slightly smaller blood drops, while thinner simulated blood will produce slightly larger blood drops. We try to use blood with a thickness that will produce a 19mm to 20mm diameter blood drop when dropped from a height of 6 feet (the supplied Standard Curve is based on this mixture of blood). Thicker or thinner simulated blood may cause your student s blood drops to be smaller or larger than the Standard Curve Diameters shown on the graph although this will NOT affect your student s ability to understand the Diameter vs. Height relationship, or answer the Training Lab Questions correctly. Remind students to measure blood drop diameter accurately to 0.5mm if possible (does the edge of the blood drop end up between mm lines on the ruler or right on a line?). Remind students there is a relationship between blood drop height and blood drop diameter (as seen in their results and on the supplied Standard Curve), however, the blood drop heights they determine when using the Standard Curve are still only an APPROXIMATE or ESTIMATED height. Students should be careful not to get the simulated blood on their clothes, etc. Some simulated bloods will stain. As an extra activity you could have students release blood drops on different materials to see the affect. Smoother materials (like glass) should produce drops with a smooth edge. Rougher materials (like textured wallpaper, ceiling tile) should produce drops with more spikes. Typical Results: Please see the KEY to the Questions that follows these Teacher Notes. Although student results can be variable, everyone should see there is a relationship between the height a blood drop falls and the diameter of the resulting blood drop. The results students get from their blood drops will NOT affect their ability to answer the Training Lab Questions correctly. 32

18 QUESTIONS BLOOD AS EVIDENCE BLOOD DROPS DRIPPING FROM A WOUND NAME KEY 1. Observe the blood drop points you plotted on the Blood Drop Diameter vs. Blood Drop Height graph and finish the following statement. My blood drop points would produce a Standard Curve that is (choose one): almost exactly like the Standard Curve that is already on the graph. somewhat similar ANSWERS to the Standard WILL VARY Curve that is already on the graph. not much like the Standard Curve that is already on the graph. 2. How can you look at a blood drop and determine if it dripped straight down from a wound or hit the floor at an angle (from a bleeding person that was running)? A BLOOD DROP THAT FALLS STRAIGHT DOWN WILL BE CIRCULAR, WHILE A BLOOD DROP THAT FALLS AT AN ANGLE WILL APPEAR OVAL-SHAPED. 3. How does a blood drop that falls on glass appear different from a blood drop that falls on a piece of paper? A BLOOD DROP THAT FALLS ON A SMOOTH SURFACE, LIKE GLASS, USUALLY HAS A SMOOTH EDGE, WHILE A BLOOD DROP THAT FALLS ON PAPER USUALLY HAS A ROUGH EDGE WITH MORE SPIKES. 4. You are looking at a blood drop from a crime scene that has a diameter of 16.5 mm. From approximately what height did this blood drop fall? AROUND 2 5 THE CASE OF THE PARKING LOT MURDER You are investigating a murder that occurred approximately four hours earlier in the day. A witness saw two men arguing in a parking lot. She did not recognize either of the men, but described them both as being about 6 feet tall. The witness saw one man pull out a knife and swing it several times at the other man. The attacked man took a few steps back and stood for several seconds as he looked at his wounds which appeared to be bleeding. He then pulled out a gun, shot the man that was holding the knife, and ran from the scene. The man that was shot died of his wounds, and you are now on a search for the missing suspect. You find blood drops on the parking lot where the shooter stood and bled from his knife wounds. These exact same blood drops are visible on the next page, ready for your analysis (carefully measure blood drop diameter to the nearest 0.5mm). You decide to call area hospitals and see if anyone recently checked themselves in for treatment of lacerations (cuts). You discover that FIVE people recently checked in for laceration injuries: Patient A cut on the right calf (below the knee) Patient B cut left calf (below the knee) and left cheek Patient C cut along right hip region (just below waist) Patient D cut along left hip region (just below waist) and right cheek Patient E cut on left shoulder and forehead 33

19 #2 #5 #1 #3 #4 Complete the Blood Drop Evidence Form below and then answer the questions that follow about the crime. Evidence # Location of Blood Drop Diameter of Blood Drop (mm) Approximate Height Blood Drop Fell BLOOD DROP EVIDENCE FORM Parking Lot Parking Lot Parking Lot Parking Lot Parking Lot 17.5mm 19.5mm 17.5mm 19.5mm 19.5mm 3 2 to to to to to 5 3 SHOULD 5. In your opinion, did all the evidence blood drops fall from the same height? BE NO If you answered YES for Question #5 from approximately what height did all the blood drops fall? If you answered NO for Question #5 from how many different heights do you think the blood drops fell? TWO 6. Based on the height(s) the evidence blood drops fell - list the body area (or body areas) where you think the suspect was injured by the knife. SOMEWHERE ABOUT 3 FEET HIGH NEAR THE HIP/WAIST AREA SOMEWHERE A LITTLE ABOVE 5 FEET HIGH AROUND THE FACE/HEAD AREA 7. Based on the blood drop evidence you analyzed, which patient is most likely your suspect? SUSPECT D INJURED AT HIP AND CHEEK 34

20 THE CASE OF THE BLOODY KNEE You have been called to investigate a robbery at a local business. A single employee was working at the time. The employee stated that two men entered the business. One of the men quickly pulled a 2-foot tall stepladder (used to reach items on the store s top shelf) to the corner of the store near the door. The man stood on top of the stepladder, and pulled a plug on a security camera located there presumably so they could not be filmed. The man jumped down, picked up the ladder, then threw it across the store at the employee and demanded money. The employee was scared and gave the men all the cash that was in the register - $2,500. The men quickly left with the money and the employee immediately called the police. You notice several fresh drops of blood on the floor - three blood drops next to the cash register and four drops in the corner of the store beneath the disabled security camera near the door. These exact same blood drops are visible below, ready for your analysis (carefully measure blood drop diameter to the nearest 0.5mm). The employee states that all the blood drops came from a cut on her knee. She shows you the fresh cut on her knee and explains that the stepladder has a sharp edge and as the thrown ladder bounced across the floor it hit her knee and cut it. She says the drops by the cash register must have fallen while she removed the money, and the drops by the camera must have fallen as she stood near the door waiting for the police to arrive. You ask the employee how tall she is she looks a little confused, but answers 5 foot 6 inches tall. #1 #2 #4 #5 #3 #7 #6 Blood Drops By Cash Register Blood Drops Beneath Security Camera and Near Door 35

21 Complete the Blood Drop Evidence Form below and then answer the questions that follow about the crime. BLOOD DROP EVIDENCE FORM Evidence # Location of Blood Drop Cash Register Cash Register Cash Register Security Camera Security Camera Security Camera Security Camera Diameter of Blood Drop (mm) Approximate Height Blood Drop Fell 15mm 15mm 15mm 18mm 18mm 1 5 to to to mm 8. Do all the evidence blood drops by the cash register appear to have fallen from the same height? YES 15mm to Which evidence blood drops by the cash register could have fallen from the employee s knee as stated? #1, #2, #3 10. Do all the evidence blood drops by the security camera and door appear to have fallen from the same height? NO 11. Which evidence blood drops by the security camera and door could have fallen from the employee s knee as stated? #7 12. A blood test completed back at the lab confirms that all the evidence blood drops belong to the employee. Soon after you complete your analysis of the blood drops you file a report to have the employee arrested for faking a robbery and stealing the $2,500 from the cash register. The employee later admitted her guilt, stating that she had worked alone to steal the money and made the robbery story up. Everyone in the crime lab is amazed that you solved this crime based on only a few drops of blood. Recreate (describe) the events you think happened as the employee stole the money including your conclusions about each of the evidence blood drops. THE EMPLOYEE PLACED THE 2-FOOT TALL STEPLADDER UNDER THE SECURITY CAMERA AND IN THE PROCESS CUT HER KNEE ON THE SHARP EDGE OF THE LADDER. SHE CLIMBED TO THE TOP OF THE LADDER AND UNPLUGGED THE SECURITY CAMERA SO IT COULD NOT RECORD HER AS SHE TOOK THE MONEY. WHILE ON TOP OF THE LADDER BLOOD DROPS #4, 5 AND 6 DROPPED TO THE GROUND FROM THE LADDER S HEIGHT + HER KNEE HEIGHT. BACK ON THE GROUND DROP #7 FELL FROM KNEE HEIGHT ONLY. SHE THEN MOVED TO THE REGISTER AND TOOK THE MONEY. WHILE THERE, DROPS #1, 2, AND 3 FELL FROM KNEE HEIGHT. SHE MADE THE ROBBERY STORY UP TO TRY AND COVER UP HER THEFT. 36

22 TRAINING LAB BLOOD AS EVIDENCE BLOOD DROPS FALLING AT AN ANGLE NAME Background: You just completed studying the behavior of passive blood drops that drip straight down from a wound, but not all blood drops fall straight down. Blood drops often travel at angles before hitting a surface and forming blood spatter. For example: blood drops flying away from a wound just made by a gunshot or blow. blood drops falling from a moving victim. blood drops that are flying from a swinging weapon. Angled blood drops appear oval in shape when they hit a surface and their unique shape can help you determine the direction they were flying. A collection of angled blood drops (blood spatter) in a room can help you determine where a victim was injured in a room even if the victim is no longer present. In this Training Lab you will be investigating the behavior of Angled Blood Drops falling at different angles. 1. You will be trained to observe a blood drop that fell at an angle and determine the direction it was moving. 2. You will be trained to observe a blood drop that fell at an angle and determine its Angle of Impact or Impact Angle. Procedures: Part 1 Collecting Blood Drops Released From Different Angles 1. You will need a clipboard, NINE large note cards, a covered beaker of simulated blood, a dropper, a meter stick, a protractor, a roll of masking tape, and a small stack of books. 2. When a blood drop falls straight down, or hits a wall 90 o straight on, it contacts the surface at a 90 o angle. 90 o floor wall A blood drop striking the floor or wall at a wall 30 o angle would look something like this: floor 30 o 30 In this Training Lab you will observe blood drops striking a surface o at several different angles. To simulate blood dropping at different angles you will adjust the angle of the surface the blood drops are hitting. 3. Place the clipboard on a flat table. Tape the LONG EDGE of the clipboard to the table (using pieces of tape like hinges) so you can tilt the clipboard up and down at different angles (see Figure 1 below). read angle here protractor in 10 o 20 o correct position Figure 1 How to set up the clipboard to test angled blood drops note card tape hinges note card place clipboard clip on opposite side from protractor place books behind to support the clipboard 37

23 4. Tape TWO of the large note cards on the clipboard, side by side. Orient the cards on the clipboard as shown in Figure Label one of the note cards 10 o Angle in the upper right corner along with your name. Label the second note card 20 o Angle in the upper right corner along with your name. 6. Place the EXACT CENTER of the protractor s flat edge (usually indicated by a line coming from a hole) next to the hinged edge of the clipboard (see protractor in correct position in Figure 1). The numbers along the curved edge of the protractor will tell you the angle the clipboard is raised (see read angle here in Figure 1). This number is NOT the angle the blood drop will be falling. 7. Carefully tilt the clipboard so it is tilted at an 80 o angle in relation to the tabletop (almost straight up and down). The edge of the clipboard should be next to 80 on the protractor. Place books behind the clipboard to hold it in position at this exact angle. 8. A drop of blood released from above the 80 o tilted clipboard will hit the note card at a 10 o angle (see the diagram at right). 9. Suck up simulated blood into the dropper (avoid sucking up bubbles). All drops will be released from EXACTLY 15 inches above the tabletop (hold a meter stick upright on the table next to the clipboard to measure 15 inches high). 10 o clipboard blood drop 10. Hold the open end of the dropper over the 10 o Angle note card. Gently squeeze the dropper to release THREE separate drops of blood from 15 inches each drop falling on a different location of the 10 o Angle card (the drops should not touch or overlap). You should NOT allow bubbles to form as you release drops. Add additional drops if any bubbles are present, or any drops overlap. blood 11. Leave the card on the clipboard and lower the clipboard clipboard drop slightly so it is now tilted at 70 o 20 o (measured with the protractor) and support from behind with books. This means 70 o falling blood drops will hit the note card at a 20 o angle. table 12. Release three drops of blood from 15 inches above the tabletop so they will hit the 20 o Angle note card. Add additional drops if any bubbles are present, or any drops overlap. 13. Lower the clipboard and carefully remove the two note cards with blood drops. Place the note cards with wet blood drops on a flat surface where they can dry without being disturbed. 14. Repeat the above steps to drop blood on labeled note cards from the remaining angles: 30 o Angle note card clipboard set to a 60 o angle 40 o Angle note card clipboard set to a 50 o angle 50 o Angle note card clipboard set to a 40 o angle 60 o Angle note card clipboard set to a 30 o angle 70 o Angle note card clipboard set to a 20 o angle 80 o Angle note card clipboard set to a 10 o angle 90 o Angle note card clipboard flat on the table (0 o angle) 16. Clean up your lab station and make sure all your note cards with wet blood drops are in a flat, safe area while they dry. 80 o table 38

24 Part 2 Analyzing Blood Drops Released From Different Angles IT IS POSSIBLE TO DETERMINE IF A BLOOD DROP WAS TRAVELING AT AN ANGLE WHEN IT HIT THE SURFACE 1. Observe the shapes of your blood drops that fell straight down ( 90 o angle card) and compare them to the shapes of your other blood drop cards that fell at an angle ( 80 o to 10 o angle cards). You should be able to look at the shape of a blood drop and tell if it fell straight down or fell at an angle. Draw a neat sketch, in Table 1, to show the characteristic shape of one of your blood drops that fell straight down. For comparison, also draw a neat sketch, in Table 1, to show the characteristic shape of one of your blood drops that fell at an angle. IT IS POSSIBLE TO DETERMINE THE DIRECTION A BLOOD DROP WAS TRAVELING WHEN IT HIT THE SURFACE 2. Draw arrows on your 80 o to 10 o Angle note cards to indicate the direction the blood drops were traveling when they hit the card at an angle. 3. Observe the shapes of the blood drops that fell at angles. You should be able to tell the direction a blood drop was traveling by the general shape of the blood drop. Blood drops that fall at an angle are stretched out, with one end more rounded and the opposite end more pointed. The pointed end will be pointing in the direction the blood drop was traveling when it hit the surface (the pointed end will be pointing AWAY from the source of the blood drop). The pointed end may also have a drip or tail extending beyond the blood drop. Also, if there are any satellites present they will be located around the pointed end of the blood drop (pointing AWAY from the source of the blood drop). 4. Draw TWO neat sketches, in Table 2. One sketch should show the characteristic shape of one of your 20 o angled blood drops, and the second sketch should show the characteristics of one of your 50 o angled blood drops. Label each sketch with its correct angle, and include an arrow next to each sketch to show the direction the blood drop was traveling when it hit the surface. IT IS POSSIBLE TO DETERMINE THE IMPACT ANGLE OF A BLOOD DROP 5. Pull out your 10 o Angle note card. You should be able to look at the shapes of the blood drops on this card and tell the drops fell at an angle, and even use drop shape to determine the direction the blood drops were falling when they hit the card. But, what if you wanted to know the ANGLE OF IMPACT or IMPACT ANGLE of the drops (both names simply mean the angle that the drop hit the surface). Of course, you know the Impact Angle is 10 o because you set it up this way. But, what if you didn t know the angle? The shape of the drop can also help you determine the Impact Angle. 6. Use a small millimeter ruler and accurately measure, in millimeters to the nearest 0.5mm, the WIDTH (at the drop s widest point) and length LENGTH of each of the three blood drops you dropped at a 10 o Impact Angle. DO NOT include spikes, satellites, or tails in your length measurements length (see sketch at right). Record these measurements in Table 3 Calculating The Impact Angle Of Blood Drops. 39

25 7. Repeat Step #6 and measure the WIDTH and LENGTH of all blood drops collected on all your note cards. Record all measurements in Table Calculate and record (in Table 3) the Average Blood Drop WIDTH (from your three width measurements) and Average Blood Drop HEIGHT (from your three length measurements) for the drops collected on your 10 o Angle card. Round your calculations to hundredths (2 decimal places). 9. Repeat Step #8 and calculate the Average WIDTH and LENGTH for the drops collected on all your note cards. Record these calculations in Table Finally, use the Trigonometry Formula below to calculate the Impact Angle for the drops on your 10 o Angle card. Use your Average Width and Average Height numbers when completing this calculation. You will need a scientific calculator to complete the Inverse Sine calculation (see your supervisor for help finding the correct buttons to push on your calculator for Inverse Sine ) OR simply use a Trigonometry Table that contains Inverse Sine. Round your Impact Angle calculations to the nearest, whole degree. Record your Calculated Impact Angle in Table 3. Impact Angle of Blood Drop (Approximate) = Inverse Sine of Width of Blood Drop Length of Blood Drop Example: The width of the blood drop = 5mm, the length of the blood drop = 36mm 5mm Impact Angle of Blood Drop = Inverse Sine of 36mm Impact Angle of Blood Drop = Inverse Sine of 0.14 Impact Angle of Blood Drop = 8 o (the blood drop hit the surface at an 8 o angle) 11. Repeat Step #10 and calculate the Impact Angle for the drops collected on all of your note cards. Record these calculations in Table Look over the Reference Page Trigonometry and Blood Drops Part 1 to get a better understanding of why this strange Impact Angle formula works! 40

26 Table 1 How to tell if a blood drop fell at an angle by its shape Characteristic Shape Of On Of My Blood Drops That Dropped Straight Down Characteristic Shape Of One Of My Blood Drops That Fell At An Angle Table 2 How to tell the direction a blood drop was moving by its shape Actual Impact Angle 10 o 20 o Drop 1 Width (mm) Characteristic Shapes Of Two Of My Blood Drops That Helps Indicate The Direction It Was Moving Table 3 Calculating the Impact Angle of blood drops Drop 2 Width (mm) Drop 3 Width (mm) Average Width (mm) Drop 1 Length (mm) Drop 2 Length (mm) Drop 3 Length (mm) Average Length (mm) Ave. Width Ave. Length Calculated Impact Angle 30 o 40 o 50 o 60 o 70 o 80 o 90 o 41

27 REFERENCE PAGE TRIGONOMETRY AND BLOOD DROPS PART 1 *Trigonometry is a useful math that can help you determine unknown angles and unknown side lengths around a Right Triangle (a triangle with one of its angles being 90 o ). *A Right Triangle is usually labeled like this: Angle B side a side c (hypotenuse) 90 o angle a Right Triangle Angle C side b Angle A *PROBLEM - If you knew that Angle A = 10 o and that side c was 1 foot long you could easily calculate the length of side a using the trigonometry formula: sine of 10 o = length of side a 1 foot sine of Angle A = 0.17 = length of side a length of side c length of side a 1 foot 0.17 feet = length of side a Think of sine in the above formula like a conversion factor that converts the unit degrees of an angle (10 o in this problem) into units of length (0.17 in this problem) so the problem can be worked correctly. *Scientific calculators have a sine button that will complete the conversion for you otherwise you would have to look up the conversion on a chart. *You may have also heard of cosine, and tangent. These also work like conversion factors to convert degrees of an angle into units of length in trigonometry formulas. We will only be using sine and will NOT be using cosine or tangent in this Training Lab. *PROBLEM If you knew that side a was 5cm long and that side c was 15cm long you could easily calculate Angle A using the trigonometry formula: Angle A = Inverse sine of length of side a length of side c Angle A = Inverse sine of 5cm 15cm Angle A = Inverse sine of 0.33cm Angle A = 19 o Inverse sine in the above problem is just the opposite of sine. It converts the unit of length (0.33cm in this problem) into the unit degrees of an angle (19.3 o in this problem). *Scientific calculators have an Inverse sine button that will complete the conversion for you. The Inverse sine of 0.33 = 19.3 o SO what does all this have to do with blood drops?? Flip over to the next page and see! 42

28 *When a blood drop hits a surface at an angle, it can be defined by an upside-down, right triangle! direction the blood drop was moving Angle C side a Angle B side b blood drop side c Angle A Angle A = blood drop s Impact Angle side c = Length of blood drop side a = Width of blood drop *This makes it very easy to calculate the Impact Angle of any blood drop you find! Simply use the formula: IMPACT ANGLE = Inverse sine of (Angle A) *What is the Impact Angle of this blood drop? IMPACT ANGLE (Angle A) width of blood drop side a length of blood drop side c length = 12mm IMPACT ANGLE = Inverse sine of 0.46mm (Angle A) width = 5.5mm 5.5mm = Inverse sine of 12mm find the Inverse sine of 0.46 IMPACT ANGLE = 27 o 43

29 Table of Sine and Tangent Values 1. To find the Sine or Tangent of an Angle, simply look up the angle and move over to the correct column. 2. To find the Inverse Sine of a number, simply look up the number in the Sine/Inverse Sine column and move over to the Angle column. Angle Sine Inv. Sine Tangent Angle Sine Inv. Sine Tangent Angle Sine Inv. Sine Tangent

30 QUESTIONS BLOOD DROPS AS EVIDENCE BLOOD DROPS FALLING AT AN ANGLE NAME 1. Observe the eight blood drops below. Draw a neat arrow next to each blood drop to indicate the direction the blood drop was traveling when it hit the surface. 2. Which group of blood drops do you think is easier to tell their direction of travel? (circle one) A. blood drops that fell at a 10 o to 40 o angle B. blood drops that fell at a 50 o to 80 o angle 3. Why do you need to use Inverse sine rather than just sine when calculating the Impact Angle of a blood drop? 4. Complete the following table by writing in your Calculated Impact Angles for your blood drops. Actual Impact Angles Of Blood Drops 10 o 20 o 30 o 40 o 50 o 60 o 70 o 80 o 90 o My Calculated Impact Angles For Blood Drops Draw a neat STAR below the Calculated Impact Angles you think were the most accurate. Draw a neat FROWNY FACE below the Calculated Impact Angles you think were the least accurate. 45

31 5. List TWO errors that could possibly account for any inaccurate Calculated Impact Angles while completing this Training Lab. 6. Determine the Impact Angles of the following blood drops. Remember you DO NOT include tails when measuring length! PLEASE SHOW YOUR WORK. Impact Angle = Impact Angle = Impact Angle = Impact Angle = Use the blood drops below to answer Questions #7 - #10. A B C 7. A victim is bleeding from their shoulder and left behind blood drops B, D, and E. Which of these blood drops came from this victim when they were: running fast, walking, and running medium? Choose from drops B, D, and E only! E F D running very fast? walking? running medium speed? 8. Which blood drop came from a person standing still and bleeding from their head? 9. Which blood drop came from a person standing still and bleeding from their knee? 10. A victim, bleeding from both their head and their knee, is running and leaving blood spatter drops D and F behind on the tile floor. Which drops most likely came from : their head? (choose D or F) their knee? (choose D or F) 46