1. Sit down Clear Your Desk Receive Your Quiz October 5, 2012

2. Aim: SWBAT explain how hair is tested for substances and as individual evidence October 5, 2012

3. Find the 12 differences between the two pictures. Source: http://www.smart-kit.com/wp-content/uploads/2008/03/chocolate-puzzle.jpg

4. The answers are … Source: http://www.smart-kit.com/wp-content/uploads/2008/03/chocolate-puzzle.jpg

5. Agenda Using hair in an investigation Testing hair for drugs and other substances Hair as a source of DNA

6. A Hairy Situation You are forensic scientists on the job with NYPD. You receive a call telling you that a man has been found that was murdered in Brownsville. Your arrive at the scene of the crime, to collect evidence, but the only evidence found is hair. You take the hair back to the lab and analyze it under a microscope, but the evidence is damaged and can’t be used. What are you going to do now? Turn and talk to the person sitting next to you and quietly discuss your idea.

7. A Hairy Situation Raise your hand and state one solution you came up with. Why would this be useful? What information do we need to know before we can do this?

8. A Hairy Situation To accurately use this evidence, we need to know a few things: How can we test for DNA and use hair as individual evidence? How can we test for drugs, poisons, etc? How was the hair collected?

9. Collecting Hair Hair can be scraped, plucked, or shaken from surfaces. It can also be collected by placing tape over a surface so hair sticks to it. This is due to ______________ exchange principle. Locard’s

10. Testing for substances When you go to apply for a job, you may need to be drug tested. This can be done in a few ways, including urine analysis and hair testing. Take 30 seconds to come up with an idea (individually) of why you think hair would be a good idea to test for drugs.

11. Testing for substances The hair shaft is tested for substances including poison, recreational drugs, and illegal drugs. These are present in hair because chemicals are absorbed into your skin, and this becomes part of the hair. In testing, chemicals break down keratin, which allows chemicals that were stored in hair to be released

12. Testing for substances To develop a timeline for exposure to substances, the growth rates (1.3 cm/month &.44 mm/day) are used. The hair is analyzed in sections, giving us a timeline for when people were exposed to the substance.

13. Hair as a source of DNA One final way to use hair is by extracting DNA from it. This is how we can use hair as individual evidence. If hair is forcibly removed from a victim or suspect, the entire hair follicle may be intact. Blood and tissue may be attached, which can be used for blood typing or DNA analysis