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. What is the primary purpose of a control sample in forensic DNA analysis? → To verify that the laboratory process worked correctly and detect contamination
2. Keeping a documented list of everyone in possession of an item of evidence. → chain of custody
3. Which department of the contemporary crime lab is in charge of processing evidence using chemistry, physics, and geology? → physical science
4. Luminol is used at crime scenes to detect: → Latent bloodstains that have been cleaned or are otherwise invisible
5. Touch DNA refers to DNA recovered from: → Skin cells deposited when a person handles or touches an object
6. In forensic biology, a 'negative control' sample used during DNA extraction contains: → No DNA, processed identically to evidence samples to detect contamination
7. What type of evidence is a shoe print found in soft soil at a crime scene? → Impression evidence
8. The M'Naghten standard is used to determine which legal concept? → Insanity defense
9. Which research design is most useful for establishing a causal link between childhood trauma and adult criminal behavior? → Longitudinal cohort study
10. The ABO blood typing system classifies blood based on the presence of: → Specific antigens on the surface of red blood cells
11. Polymerase chain reaction (PCR) is used in forensic DNA analysis primarily because it: → Amplifies small or degraded DNA samples into quantities sufficient for analysis
12. Which type of impression evidence can be collected from a soft surface like mud or snow at a crime scene? → Three-dimensional cast using dental stone or sulfur casting compound
13. Which type of fingerprint pattern is the most common among the general population? → Loop
14. Which of the following best describes 'luminol' and its use in crime scene investigation? → A chemiluminescent reagent that reacts with iron in hemoglobin to detect trace blood
15. What is the purpose of 'skeletal age estimation' in forensic anthropology? → Estimating a deceased individual's age at time of death from bone morphology
16. Which term describes the stiffening of muscles that occurs after death due to the depletion of ATP? → Rigor mortis
17. The presumptive color test that turns purple/blue in the presence of opioids is known as the: → Marquis test
18. What other name would you give Forensic Science? → Criminalistics
19. Antisocial Personality Disorder (ASPD) is characterized by which of the following patterns? → Pervasive disregard for and violation of others' rights
20. 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
21. Which section of the modern crime lab is in charge of examining toolmarks and gunshot residues? → Firearms
22. Which federal law governs the admissibility of scientific expert testimony in US federal courts? → The Federal Rules of Evidence (Daubert standard)
23. What is the primary purpose of CODIS in the United States? → To store and search DNA profiles from crime scenes and offenders
24. Carbon monoxide poisoning is detected at autopsy by testing for elevated levels of: → Carboxyhemoglobin (COHb)
25. What does 'forensic anthropology' primarily study? → Skeletal and decomposed human remains to assist in legal investigations
26. Which type of fingerprint is left on a surface by natural skin secretions without any additional substances? → Latent fingerprint
27. Which of the following examines how people behave and how the law is applied in both civil and criminal cases? → forensic psychiatry
28. Which statistical concept is central to interpreting DNA evidence and expressing the rarity of a DNA profile? → Random match probability calculated from population databases
29. 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)
30. What is the purpose of a 'blank' sample in forensic chemical analysis? → To detect contamination and establish a baseline with no analyte