BSFS Cheat Sheet 2026

The 30 highest-yield BSFS facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Keeping a documented list of everyone in possession of an item of evidence. → chain of custody
2. Which department of the contemporary crime lab is in charge of processing evidence using chemistry, physics, and geology? → physical science
3. Luminol is used at crime scenes to detect: → Latent bloodstains that have been cleaned or are otherwise invisible
4. Touch DNA refers to DNA recovered from: → Skin cells deposited when a person handles or touches an object
5. In forensic biology, a 'negative control' sample used during DNA extraction contains: → No DNA, processed identically to evidence samples to detect contamination
6. What type of evidence is a shoe print found in soft soil at a crime scene? → Impression evidence
7. The M'Naghten standard is used to determine which legal concept? → Insanity defense
8. Which research design is most useful for establishing a causal link between childhood trauma and adult criminal behavior? → Longitudinal cohort study
9. The ABO blood typing system classifies blood based on the presence of: → Specific antigens on the surface of red blood cells
10. Polymerase chain reaction (PCR) is used in forensic DNA analysis primarily because it: → Amplifies small or degraded DNA samples into quantities sufficient for analysis
11. Which term describes the stiffening of muscles that occurs after death due to the depletion of ATP? → Rigor mortis
12. The presumptive color test that turns purple/blue in the presence of opioids is known as the: → Marquis test
13. What other name would you give Forensic Science? → Criminalistics
14. Antisocial Personality Disorder (ASPD) is characterized by which of the following patterns? → Pervasive disregard for and violation of others' rights
15. An entrance gunshot wound typically differs from an exit wound in that the entrance wound is usually: → Smaller, more regular in shape, and may show an abrasion collar
16. Which section of the modern crime lab is in charge of examining toolmarks and gunshot residues? → Firearms
17. Carbon monoxide poisoning is detected at autopsy by testing for elevated levels of: → Carboxyhemoglobin (COHb)
18. Which of the following examines how people behave and how the law is applied in both civil and criminal cases? → forensic psychiatry
19. Which analytical technique is most commonly used in forensic labs to identify unknown substances by separating and detecting components in a sample? → Gas chromatography-mass spectrometry (GC-MS)
20. Which enzyme is primarily responsible for metabolizing alcohol (ethanol) in the liver? → Alcohol dehydrogenase (ADH)
21. The first classification system for fingerprint identification was created in 1896. → Edward Henry
22. When collecting a wet blood sample from a crime scene for preservation, a forensic scientist should: → Allow it to air dry completely before packaging in paper
23. Which phenomenon describes a suspect's false belief that confessing is in their best interest due to police deception or psychological pressure? → Coerced-compliant false confession
24. In the context of eyewitness testimony, which factor is considered a 'system variable' (controllable by the justice system)? → Lineup administration procedures
25. Which packaging material should NOT be used to store biological evidence such as bloodstained clothing? → Airtight plastic bags
26. Which of the following best describes the work done by forensic scientists? → Examine evidence
27. Which technique is used to cast three-dimensional impressions (such as footwear or tire tracks) at a crime scene? → Dental stone (plaster of Paris) casting
28. CODIS, the national DNA database used by forensic labs in the U.S., stands for: → Combined DNA Index System
29. File metadata in digital forensics can reveal which of the following? → Creation, modification, and access timestamps, as well as file author and location
30. Livor mortis (lividity) refers to the postmortem settling of blood that causes: → Purplish-red discoloration of dependent body areas due to gravity-driven blood pooling