1. (Discussion and Complete Worksheet - Firearms)
Thursday March 1, 2018
(Discussion and Complete Worksheet - Firearms)

2. The Daily CSI
Thursday, 3/1/18 ??

3. Remediation for Quiz 12 ends tomorrow!
Announcements
Remediation for Quiz 12 ends tomorrow!

4. Summative or Formative # Hold for eResearch Paper
Assignment
Summative or Formative #
Date Issued
Gone Missing Day
Last Day Accepted
QUIZ 12 S3
2/26
Friday
WS – Firearms
F11
2/27
N/A
Hold for eResearch Paper

5. Gun Shot Residue (GSR)

6. Gunshot Residue (GSR) GSR Sources: Victim Victim’s clothing Target
Shooter’s hands.

7. Gunshot Residue (GSR) Gunpowder Chemistry
Major detectable elements are: lead (Pb), barium (Ba) & antimony (Sb)
Virtually all cartridge cases are made of brass (copper & zinc)

8. Griess Test
Tests for the presence of nitrates (partially burned or unburned gunpowder)
Swab of shooter’s hand
Must produce a pattern for a distance determination

9. Results of GSR Hand Test
Negative results may be caused by:
Washing the hands
Shooter may have been wearing gloves
Lead free ammunition
A rifle or shotgun may not deposit GSR on hands

12. GSR on the hand of a suicide victim, proving he was holding the weapon when it was fired.

13. SERIAL NUMBER RESTORATION
When a serial number is stamped into a gun, the metal underneath the number is compressed & hardened.
If the number is filed-off, the hardened area may still be present.
By using an acid solution the metal can be slowly eaten away.
In this process the softer metal will be eaten away first and the number may reappear.

14. Before & After
Historically, serial numbers are successfully restored 63% of the time on steel & 54% of the time for aluminum or zinc.

15. FIREARMS EVIDENCE COLLECTION
Make sure the weapon is unloaded!
REVOLVERS
Indicate location of fired & unfired ammunition
AUTOMATICS
Check magazine for number of rounds
Fingerprint magazine
Place ID tag on trigger guard

16. FIREARMS EVIDENCE COLLECTION
AMMUNITION
Write on base or nose
Package in pill box or envelope
Wrap in tissue to protect

17. FIREARMS EVIDENCE COLLECTION
CLOTHING
Protect & preserve any residue
Air dry if wet
Package separately in paper bags
Establish CHAIN OF CUSTODY

18. Complete Worksheet Firearms