- Arson
- Art Forgery
- Art Identification
- Artificial Fibers
- Ashbaugh, David Robinson
- Aspermia
- Asphyxiation (Signs Of)
- Assassination
- Assassination Weapons, Biochemical
- Assassination Weapons, Mechanical
- ATF (United States Bureau of Alcohol, Tobacco, and Firearms)
- Automated Fingerprint Identification System (AFIS)
- Automobile Accidents
- Autopsy
- Autorad
- Aviation Security Screeners, United States
