North Carolina only event. Do not use the national rules.
Description: This is a Lab based event. Teams will be given a crime scenario which they will be asked to solve based on evidence they gather and test. The Chemical Evidence topic for 2014 is powders (identifying unknowns and answering procedure and safety questions). The Physical Evidence topic for 2014 is fibers, firearms and toolmarks. Teams will then be asked to analyze the information they have gathered to identify a suspect and solve the crime.
Teams MUST bring chemical splash goggles and a writing instrument. Teams may also bring spot plates, test tubes and test tube holders or any containers in which they can perform the tests, droppers, popsicle sticks, spatulas, plastic spoons, tongs, forceps, &/or stirring rods for handling materials, pH paper, flame test equipment (cobalt blue glass, wire holders, etc), a thermometer, a ruler and/or calipers, a wash bottle of distilled water, hand lenses or loupes, paper towels, a disposable cup for solid waste, writing instruments, one 8.5” x 11” two-sided page of notes containing information in any form from any source, and one non-programmable calculator.
***SAFETY ISSUE*** In addition toOSHA approved chemical splash goggles with indirect vents, teams also MUST wearclosed toed shoes,pants/skirts that cover legs to the ankle, AND a lab coat/apron that reaches below the knee or they will not be allowed to participate. Long hair must be tied back. In addition, any teams seen handling materials in an unsafe manner will be disqualified from the event.***SAFETY ISSUE***
Event Leaders will provide a proper lab environment, all evidence to be collected, additional equipment necessary to perform tests on the evidence, the official test and answer sheet.
Scoring: High score wins. Points are earned for proper identification of evidence as well as analysis of the crime. Ties will be broken by the best Chemical Evidence score. Points are distributed as follows: 3.a. Chemical Evidence 50%, 3.b. Physical Evidence 30%, 3.c. Analysis 20%
- Be sure to follow all safety requirements! Safety issues will NOT be arbitrated.
- Event leaders will not answer questions on testing procedures (for example- how to perform a burn test on fibers) nor will they provide a copy of the rules or a list of the possible unknowns. Teams should already know procedure, and should include a list of the possible unknowns in their allowed notes if they cannot remember. Event leaders WILL answer safety questions, and stop students from performing a test in an unsafe manner.
FIBER AND POLYMER KITS:
NC is continuing to offer a complete kit containing the following fibers: Cotton, Polyester, Nylon, Wool, Spandex, Silk, Linen and the following polymers: PETE, HDPE, PVC, LDPE, PP, PS, PMMA, and PC. Each kit contains enough of each material to perform several tests. It includes a sample of all 7 fibers and all 8 polymers that are used in the CrimeBuster or Forensics event. The kit comes with basic instructions as well. We are currently working on updating our online store for ordering. In the meantime you can send an email to the State Office.
How to identify unknown fibers based on their flame test characteristics. Start with fibers you know and test them all, being careful to observe and record all characteristics of the test. It is much easier to make your own chart to follow than to download one, since you will recognize the same characteristic in a fiber more easily if you described it in your own words rather than trying to match it to someone else's description.
How to do a polymer density test. Follow the flow chart and see if each polymer sinks or floats in the liquid it's placed in to determine its relative density and come to an identification. If a polymer is floating, make sure it is actually floating and not sticking to the surface via surface tension. Do this by forcing the pellet to submerge, then see if it floats back up.
Performing powder tests in the Forensics event. The process here is the same as in the Crime Busters event.
More powder tests. Always write down everything!
Not in 2013 NC rules. Performing chromatography tests. Ideally you would not want the filter paper to touch the side of the cup, you would suspend it from a straw or rod of some sort.
The divide and conquer approach. One teammate works on powder identification (note the proper use of wafting to identify smells) while the other teammate works on the fingerprint IDs.