Elitch Gardens. and. Forensic Science Workbook. Mad Science Whodunnit Challenge 2015

Transcription

1 Elitch Gardens and Forensic Science Workbook Mad Science Whodunnit Challenge 2015 Name: Mad Science of Colorado 8380 Zuni St Denver, CO

2 Whodunnit Challenge Forensic science is the use of the scientific method to gather and interpret evidence in a crime, with the intent to present the evidence in a court case. Forensics utilizes a number of scientific disciplines, including biology, chemistry, entomology, geology, and physics. It is the job of crime scene analysts to work together with law enforcement to determine what pieces of evidence are important to the crime and piece together what happened. Each Mad Science station will give you a opportunity to look at and analyze the clues found at the scene using: Fingerprint Analysis Forensic Chemical Analysis Soil Analysis Fiber Analysis It will be up to you to determine what evidence is relevant to the crime, find out what happened, and which of the suspects committed the crime! Once you have made your guess, the Mad Scientist at the ***** station can tell you whether you've found the correct perpetrator! Each station will also provide information to answer the questions on the last page of your workbook. Once you have completed the challenge, return the completed page to any Mad Scientist to enter your class in a drawing to win a Mad Science party.

3 Whodunnit Challenge The Crime Sometime in the evening of May 13th, the Popcorn District concession stand in the Entry Pavilion of Elitch Gardens was broken into. The thief made off with the stand's entire stock of cotton candy, amounting to several hundred dollars worth of sugar. Several suspects have been identified based on motive and/or opportunity and park management has provided information on each suspect. The Crime Scene The crime took place in the back room of the Popcorn District concession stand. The entire stock of cotton candy was missing. A crime scene unit processed the scene and found the following: fingerprints on the door, cotton candy machines, and counter tops; a spilled bottle of water on the floor in between the location of the cotton candy and the door; smudges of white powder in area of the cotton candy; dirty footprints on the floor of the room. The Suspects Suspect #1 works nights at the park as a Park Services employee, cleaning the park. Suspect found the door to the Popcorn District employee entrance unlocked and ajar. Subject entered the back room, saw the mess and missing cotton candy, and called the Park Manager, who notified law enforcement. Possible Motive: recently applied for a day position in the park; was passed over for job. Opportunity: works nights at the park; has keys to all park venues. Alibi: arrived at park at 11 pm for shift, cleaning park until crime scene found at 2:14 am. Suspect #2 works the Popcorn District concession stand during the day. Suspect worked a short shift at the Popcorn District the day before, making cotton candy in preparation for the following days. Clocked out of the park at 4:03 pm. Possible Motive: overheard by coworker saying tired of spending my day covered in sugar. Opportunity: working alone in the concession stand from 2:00 pm until 4:03 pm. Alibi: after leaving work, Suspect went home and spent night on the couch, binge watching Game of Thrones alone. Suspect #3 was fired by Park Manager one week ago. Possible Motive: angry at Park for being fired Opportunity: unsure Alibi: was at a concert at the Pepsi Center with friends from 6pm until 11:30. Suspect #4 is the popcorn vendor for Elitch Gardens. Possible Motive: Trying to boost sagging popcorn sales at park. Opportunity: unsure Alibi: was at a business dinner with manager of local movie theater, trying to convince theater to sell more popcorn.

4 Fingerprint Analysis Every day, we leave fingerprints on everything we touch. Each individual's fingerprint is unique; even identical twins have different fingerprints. These unique prints can be used in identification, for background checks, biometric security, and criminal investigations. When a person touches an object, the oils on their fingers stay on the object, leaving behind an impression of the person's fingerprint. If there is dirt or other visible particles on the person's finger, the print may be easy to see. If the person's hands are clean, tools can be used to create a visible fingerprint. Dark powder can be brushed over the fingerprint and will stick to the areas of oil, creating a visible print. The print can then be photographed or lifted using adhesive. Each fingerprint is made up of ridges, or raised areas, and furrows, recessed areas. These ridges and furrows create the patterns of fingerprints; the oils from the ridges of a print are what sticks to an object and is left behind. Fingerprint patterns come in three basic types: loops, whorls, and arches. Fingerprin t identificati on also requires known fingerprint s to compare the found print to. Fingerprin t samples can be taken, and compared to a found print to determine who the print belongs to. Fingerprint identification also requires the discovery of an unsmudged print; if a print has been smudged or disturbed in any way, it can be difficult to compare it to another print. Fingerprinting is one of the oldest examples of forensic science and has been used for more than 100 years!

5 Chemical Analysis Chemistry plays a vital part in forensics, allowing for the identification of unknown substances. Most chemical identification today is performed using instruments, including a gas chromatograph and mass spectrometer. These instruments break up unknown substances into smaller identifiable molecules and arrange them on the instrument display, to create a pattern unique to that substance. The patterns of unknown substances can be compared to patterns of known substances (known as reference samples) to find a match. GC-MS results for the molecule CH 2 CH 3 Simpler chemical analyses can be performed in the field without the use of instruments. Knowing how certain substances react when treated with a certain chemical can allow us to identify unknowns by observing the reactions. We will be comparing a number of known chemical reactions to the reaction of our unknown powder found at the scene to determine what the powder is.

6 Soil Analysis Soil analysis is the use of soil science to aid in criminal investigations. Similar to fingerprints, soils from different areas have different characteristics. If a sample of soil taken as evidence from a crime scene can be matched to a specific place, that can give investigators an idea of where the suspect was before the crime was committed. Soil analysts look at several identifying characteristics, including sediment, color and soil structure. Sediment refers to the rock particles that make up the majority of the soil. Analysts look at rock type, particle size, and weathering to determine where the soil may have come from. Color can be indicative of the type of minerals or compounds found in the soil. Light gray or whitish soil may indicate the presence of lime (calcium oxide or calcium hydroxide). Darker brown or black soil often contains organic material, while red, brown, or yellow soil indicates high amounts of iron. Soil Structure refers to other physical characteristics of the soil, including sediment size, which determines whether the soil is sandy, silty, or clay-like; moisture content; and how the soil clumps. Individually, these characteristics may not tell scientists much, but when put together, they often create a distinct picture of where the soil came from. Additionally, if soil from a crime scene can be matched to a suspect s shoe, that provides evidence linking the suspect to the scene of the crime.

7 Fiber Analysis The clothing we wear and the fabrics we use are made of many different materials. These materials are made of a number of different fibers; including man made, animal, and plant-based. Plant based fibers include cotton and linen; animal based fibers include silk and wool. Man-made fibers are numerous and include nylon, rayon, polyester, and acrylic. When a piece of clothing or material catches on something, it may pull a piece of the fiber or material off. Fibers found at a crime scene may be used to link a person to the scene; however, in most cases, fiber evidence alone is not enough to confirm a suspect s involvement in the crime. Additionally, fibers must be matched to a source material in order to be of much use. Fiber evidence is generally used in combination with additional evidence found at the scene. The simplest way of comparing fibers for identification is to observe the individual fibers under magnification. This can often tell us if a fiber is natural or man-made, as man-made fibers are generally smoother than naturally occurring ones. Natural fibers are often shorter and have been woven or twisted together to create longer strands. Chemical tests can also help narrow down the source of the fiber; man-made fibers will generally melt more quickly than natural ones, and animal based fibers will dissolve in bleach while plant based and man-made fibers will not. Individual fibers from cotton, wool, and rayon at 40x magnification These analyses are helpful in determining in the source of the fibers, but may not aid in the investigation of the crime unless the fibers can be directly linked to the suspect. If investigators can prove that a fiber found at the crime scene likely came from a tear in the suspect s jacket, that

8 provides strong evidence the suspect was at the scene. Complete these questions and the form below and turn in the form to any Mad Scientist at the park. 1. What substance on people s fingers allows a fingerprint to be transferred to an object? 2. How does chemical analysis allow investigators to identify an unknown substance? 3. Based on a soil analysis, you would expect the rocks at Red Rocks to be high in what mineral? 4. How can you tell man-made fibers from naturally occurring fibers? 5. After observing the clues at each station, which suspect do you think is the perpetrator? STUDENT NAME SCHOOL NAME GRADE TEACHER NAME CITY COMMENTS WHAT WAS YOUR FAVORITE MAD SCIENCE ACTIVITY?

9 Additional Questions 1. After observing the fingerprints found at the crime scene, who should be included in your list of suspects? 2. After performing the chemical analysis, what sort of white powder was found at the scene? Where might it have come from? 3. What did the soil analysis tell you about where the suspect might have been before committing the crime? 4. What sort of fibers were found at the scene? Can they be linked to any of the suspects? 5. If a person's fingerprints are found at the scene of a crime, should they automatically be included in the suspect list? Why or why not? 6. Why would it be preferable to perform a chemical analysis in a laboratory rather than in the field? 7. What are the limits in using soil and fiber analyses to find a suspect? Would a single soil or fiber analysis provide enough evidence to convict someone of a crime?