Lock Identification & Key Systems Flashcards

A tubular (ace) lock, often found on vending machines, is identified by its circular keyway. The primary forensic concern with these locks is:

Answer: Inexpensive tubular lock picks or 7-pin tubular pick tools can open many in seconds

Widely available tubular lock pick tools can decode and open most standard tubular locks quickly, and the attack leaves minimal evidence compared to forced entry.

The Abloy disc detainer lock is considered high security partly because it has no:

Answer: Springs in the locking mechanism

Abloy locks use rotating discs with no springs; without springs there is no binding when picking, making traditional pick techniques ineffective.

A forensic locksmith is asked to determine if a lock was opened with the correct key or by manipulation. The presence of which evidence would MOST strongly support legitimate key use?

Answer: Consistent wear patterns on key cuts matching the lock's bitting

Consistent wear patterns on key cuts that exactly match the lock's bitting sequence indicate the lock was regularly operated by a properly cut key.

In a restricted keyway system, the restriction is enforced through:

Answer: Patent protection and contractual agreements limiting blank availability to authorized dealers

Restricted keyway systems rely on patents and controlled distribution agreements to prevent hardware stores and unauthorized locksmiths from obtaining or duplicating blanks.

Which feature of a high-security cylinder like ASSA Abloy or Mul-T-Lock makes traditional bump key attacks ineffective?

Answer: A secondary locking element (sidebar or rotating disc) requiring additional alignment beyond pin shear

Secondary elements like sidebars or rotating discs require a key to align a second set of security features beyond the primary shear line, which bump keys cannot activate.

When a forensic locksmith decodes a lock by reading the bitting without disassembly, which tool is typically used?

Answer: A feeler gauge or specialized decoder tool inserted into the keyway

Decoder tools (often called pick decoders) are inserted into the keyway and read the height of each pin stack through tactile or visual feedback to determine the bitting code.

A 'key-in-knob' (KIK) cylinder differs from a mortise cylinder primarily in that:

Answer: KIK cylinders have a tailpiece that rotates a cam, while mortise cylinders thread directly into a mortise lock case

KIK cylinders use a rotating tailpiece to actuate the knob mechanism, whereas mortise cylinders thread into the mortise lock body with a cam or tailpiece that operates the lock's internal levers.