CFL Cheat Sheet 2026

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

1. Which type of automotive lock mechanism uses flat, spring-loaded wafers as its primary tumbler components? → Wafer tumbler lock
2. Which component of a mechanical combination lock is most often targeted when attempting a 'manipulation' attack by feel? → The fence contact point with wheel notches
3. What is the forensic significance of finding burn marks and oxidized metal around a safe's hinge area? → Evidence of a torch attack focused on melting or cutting the hinge pins or weld seams
4. What is the most important ethical consideration for CFL professionals in key & lock examination? → Maintaining objectivity, integrity, and confidentiality in all professional work
5. When examining a fire-rated safe, what does an 'UL Class 350 – 1 Hour' label indicate? → The safe interior will not exceed 350°F for one hour in a standardized fire test
6. Which safe attack method involves cutting around the entire perimeter of a safe door with a power tool to separate it from the body? → Ripping
7. Which method provides the most reliable assessment of a specific lock's pick resistance? → Skilled manual picking attempt by a trained forensic locksmith under controlled conditions
8. Why is it important to understand different types of keyways in forensic locksmithing? → To identify key duplication methods.
9. What is the primary purpose of a forensic locksmith maintaining a reference collection of locks, keys, and components? → To compare questioned items against known exemplars during examination
10. In forensic analysis of a safe room or vault, which attribute of the door and frame assembly is MOST critical to document for evidence of forced entry attempts? → Deformation, tool marks, and integrity of the door swing clearances and frame anchors
11. When documenting vulnerabilities, what should a CFL note about a lock cylinder's projection beyond the door face? → Excessive projection increases the risk of a cylinder pull attack by providing leverage
12. What is the role of a forensic locksmith in evidence handling? → To open locks and preserve the integrity of the evidence
13. What is the first step in forensic analysis during a crime scene investigation? → Securing the crime scene
14. Which characteristic of a hacksaw blade is most useful for individualization of a tool mark on a cut lock shackle? → Random nicks, bent teeth, and wear patterns along the blade edge
15. When a CFL collects metal filings from below a drilled lock, how should these be packaged? → In a sealed paper envelope or rigid pill box with evidence tape and proper case labeling
16. A Kwikset SmartKey cylinder uses a redesigned mechanism primarily to prevent which attack vector? → Key bumping
17. What does 'error rate' refer to in the context of forensic locksmith methodology compliance? → The known frequency with which the examination technique produces incorrect results
18. What is the most important ethical consideration for CFL professionals in tool mark analysis? → Maintaining objectivity, integrity, and confidentiality in all professional work
19. A forensic report must note that the lock was examined 'in situ' when: → The lock was examined at the crime scene without being removed
20. A CFL is asked to determine if a vehicle's ignition lock was hot-wired after a theft. The MOST relevant forensic evidence in the lock itself would be: → Toolmarks consistent with bypass tools inside the steering column lock
21. A tubular lock examined by a CFL shows radial scratches symmetrically arranged around the plug face. This pattern is MOST consistent with: → A tubular lock pick or impressioning tool attack
22. A 'valet key' in an automotive security system is specifically designed to do which of the following? → Start the engine and open doors while restricting access to locked storage areas
23. A key with cuts on both sides of the blade that can be inserted in either orientation is called a: → Reversible (or double-sided) key
24. What material is commonly used for vault walls to ensure maximum security? → Reinforced steel or composite materials
25. In wafer tumbler locks, what forensic indicator would suggest manipulation rather than the correct key was used? → Asymmetric wear or scoring on individual wafers
26. The TL-30 rating for a safe indicates it can resist a tool attack for a minimum of: → 30 minutes using common mechanical and electrical tools
27. What is the ethical obligation of a forensic locksmith regarding the quality of their work? → To ensure that all work is conducted accurately and ethically
28. When a forensic locksmith's written report contains a factual error discovered after submission, what is the appropriate course of action? → Issue a supplemental or amended report immediately and notify retaining counsel
29. A forensic locksmith testifies that a tool mark examination is 'inconclusive.' This conclusion means: → The evidence was insufficient to either identify or exclude the suspect tool
30. Participation in professional development workshops specifically focused on forensic case studies benefits a CFL primarily by: → Exposing them to emerging techniques, evolving standards, and peer critique of methodology