Lock Identification & Key Systems Flashcards

A key with cuts on both sides of the blade that can be inserted in either orientation is called a:

Answer: Reversible (or double-sided) key

Reversible keys have identical or mirror-image bitting on both sides, allowing insertion in either direction without affecting the lock operation.

During an impressioning attack, the blank key is marked by the binding pin leaving an impression. What characteristic mark does a forensic examiner look for on a successfully impressioned key?

Answer: Bright, shiny marks at specific bitting positions from metal contact

Binding pins leave bright, shiny witness marks (bright spots) on the key blank at the exact positions where cuts need to be filed, guiding the impressioning process.

A disc detainer lock, commonly used in high-security padlocks, operates on which principle distinct from standard pin tumbler locks?

Answer: Rotating discs with cutouts must align to form a continuous channel for a sidebar or bolt to pass

Disc detainer locks use rotating discs with precisely placed cutouts; the correct key rotates each disc to align all cutouts, allowing a sidebar or bolt mechanism to travel freely.

In a grand master key system, what is the relationship between the grand master key (GMK) and a change key (CK)?

Answer: The GMK operates all locks in the system while each CK operates only its designated lock

In a grand master key system, the GMK sits at the top of the hierarchy and operates every lock in the system, while each change key operates only the specific lock it was cut for.

A Kwikset SmartKey cylinder uses a redesigned mechanism primarily to prevent which attack vector?

Answer: Key bumping

Kwikset SmartKey was specifically engineered with a sidebar and different internal mechanism to resist bump key attacks that plagued traditional Kwikset pin tumbler cylinders.

When documenting a crime scene lock, the forensic locksmith should record the lock's 'hand' designation. What does 'hand' refer to in lockset terminology?

Answer: The orientation (left or right) of the hinge side and swing direction of the door

Lock 'hand' designates the combination of hinge side and swing direction (e.g., right-hand reverse) and is critical for determining the correct replacement hardware and documenting installation context.

Magnetic key systems use internal magnets rather than mechanical cuts. Their primary forensic significance when found at a crime scene is:

Answer: They leave no traditional picking marks, requiring the examiner to consider other bypass methods

Magnetic locks leave no traditional pin-picking or bumping evidence, so the forensic examiner must look for other bypass indicators such as shim marks or electronic manipulation evidence.