Forensics

Freaking longest test in the world (at nationals, at least). Make sure to actually complete the crime scene analysis paragraph because it's worth a LOT of points

Definitely get the paper chromatographies done in the very beginning so there is time for the ink to travel. Meanwhile, work on the other parts of the test.

if you are short on time, start scanning through the test for easy answers because there is always a handful of them.

For identifying plastics: we bought a kit from sci oly with the plastics needed. The test uses the same exact plastics, so honestly, don't waste your time trying to identify them the right way with the tests and just like memorize the shapes of the pieces since every type of plastic is cut in a unique shape.

We need a better way to ID chemicals because it's not worth the time to legit identify them with our tree, which takes just way too long

Definitely make sure that you do the rf calculations for the chromatographies because measuring the distance the ink travels is a lot faster that identifying other things.

we didn't even get time to ID hairs/fibers, maybe brian knows more re: that...

Stuff to know that we probably should have:
 * The way the plastic is created (know this for EVERY plastic; just identify if it's formed by condensation or addition)
 * the 4 steps to DNA chromatograms or something like that (BRIAN, what was it again??

oh yeah, don't forget, long pants, close toed shoes, lab coats, goggles with INDIRECT vents

and that's all i can remember.

and here are mike wu's tips from before. this is actually really good advice that brian and i completely forgot about, so actually follow his tips..:

 General Tips:

Work. FAST. Work. FAST. Work. FAST.

Forensics is all about speed. You may find spare time at the regional competition, but at states you'll have barely enough time to finish everything, and at nationals, you actually won't even finish. Practice all the experimental events, especially quantitative analysis, before the competition.

Make sure you have everything in the box. And don't leave the box behind :-P.

The parts that take up the most time during the event are: Quantitative and Chromatography. Water Testing comes a close second. You want those two to be equally distributed so that you and your partner both have a chance to finish what they need on the test.

The essay section is usually worth a huge amount of points compared to the individual questions from the other sections. You definitely do not want to leave it blank. However, by its nature you're forced to do it in the last 5-10 minutes, since you need the evidence from your other sections, so make sure one person drops everything they're doing w/ 5-10 minutes left and starts cracking on it. Make sure you clearly state who you think did it and directly reference evidence that supports your conclusion. You can also try to explain why some evidence that doesn't support your conclusion is faked/planted/irrelevant/inconsequential/circumstantial. If you can make up a motive that makes sense, put it in.

Clean up is also important. The person who is not writing the essay is cleaning up everything. Don't make a mess, as they do take off majorly for points on that.

2010-2011 Sections (Starred consistently appear, hyphenated rarely appear)


 * Quantitative Analysis: Make sure you have a procedure you know by heart to determine what a substance is. Do at least one practice for this before states, so that you actually have done what you're doing, not just know it. Definitely have a chart on the cheat sheet so you don't waste time remembering. Uses, structure, common name, and above all their chemical properties will be tested on. Although all the powders are white/translucent, you can still identify based on structure if you're unsure (esp salt). Practice makes perfect.


 * Plastics and Fiber Analysis: A variety of things will be asked, know how to test for which plastic it is, know the recycling codes, full names, their structure, uses. Fibers know how to distinguish man-made vs animal-based vs plant-based, how each reacts to flame, it's general texture as well. Hair structure + species ID also happens..


 * Chromatography: Expect to actually do lots TLC and paper chromatography test at nats, whereas states expect results, then questions (and maybe a real paper chromatography or two). Also, know gas/column/liquid chromatography also. Rf is very important to know.


 * Spectroscopy: Mass spectroscopy, seperate by m/z ratio, inertia. Know stages + parts of mass spectroscopers, but most of the time they will just ask you to match peaks on m/z graphs.


 * Fingerprints - match fingerprints, know types of fingerprints (more than just loop, whorl, arch though), know methods of fingerprinting, including chemicals used + what said chemicals bind to.

DNA: know PCR + subsets, different types of repeating DNA fragments, different ways to match people's DNA

Glass - Know refraction, be able to identify which crack in the glass came first, not 100% sure what else could come up

Entomology - Life cycle of blow flies, order of succession, time for decomposition, degree-days + maturation of insects


 * Blood typing: ABO groups, Rh groups. Antigens are present on the surface of blood cells + determine which type you are. Antibodies are present in plasma, and for a person they have the antibodies for the antigens that they do not have. To test for blood groups, mix blood cells w/ Antigen-A and Antigen-B (often shortened to Anti-A/Anti-B). If it agglomerates (clumps), then the blood cell contains that antigen. There is also blood typing for different animals (they like fish, camels, and amphibians in comparison to mammals)

Blood spatters: Know that the tip of a blood splatter points to the direction of travel, how to calculate the angle from vertical that the splatter appeared w/ sin(theta)=width/length of the blood droplet. Know how blood splatters change otherwise in resulting droplets from

-Seeds and Pollen: Matching, know how seeds may spread due to wind, animals, flowing water.

-Tracks and Soil: Match, know diff between cast and print?, know diff between loam, silt, sand, clay, gravel etc.

-Bullet Striations: Simple matching, has come up once on actually forensic competitions I've taken. Know what causes bullet striations (grooves), ridges on barrels = upraised, lands = carved out of barrels.

yup, so basically michael is right. none of the unstarred stuff even appeared on our test, although tracks to appear sometimes..