Depressants- depresses the functions of the central nervous system, calming irritability and anxiety. (barbiturates, alcohol, methaqualone, and valium)
Stimulants- substance taken to increase alertness or activity. (amphetamines, cocaine, caffeine, nicotine)
Anabolic steroids- chemically related to the male sex hormone testosterone. Promotes the secondary male characteristics and accelerates muscle growth. Has not been found that they will increase strength and performance. Can cause liver cancer, infertility, halting bone growth and diminished sex drive.
Drug ID Methods:
Screening tests include color tests and microcrystalline tests
Marquis Reagent- turns purple with heroin and morphine, orange brown with methamphetamines
Dillie-Koppanyi- violet blue when comes in contact with barbiturates
Duqenois-Levine- purple for marijuana
Van Urk- blue-purple when in contact with LSD
Scott test- blue with cocaine present
Gas chromatography- separates drugs into pure forms for tentative id
Mass spectrometry- specifically identifies a drug when in pure form- no two drugs can produce the same fragmentation patterns.
Collecting, preserving, and securing forensic evidence
The successful outcome of a criminal investigation is almost always directly related to the manner in which evidence is collected and preserved.
1st officer at the scene- Helps victims, then secures crime scene
Steps to thoroughly record the crime scene
Crime scene search patterns- line, spiral, zone, grid
Packaging evidence- Package each item in separate containers and label accurately
- Clothing is air dried before packaging in paper bags
- Charred, burnt debris, explosive residue, glass, hair and fibers are placed in
airtight glass jar
- Fingernail scrapings are placed in sealed, airtight container
- Druggist fold
Standard reference sample- sample from victim, suspect, or other known source used to compare against evidence found at the crime scene.
Chain of evidence- continuity of possession