What needs to be clarified
Assess recorded contact features, then compare the questioned mark with experimental screwdriver marks, distinguishing general dimensions from individual surface details.
Materials to prepare
- Preserved lock component bearing the mark, with packaging
- Submitted screwdriver and record of its edge condition
- Scaled discovery photographs and item collection records
What to compare
Document the original mark and edge before testing, noting dirt and damage. Compare form, size, contact direction and available microscopic detail. Make controlled exemplars in suitable material; assess feature repeatability, similarities among manufactured tools and significant differences between the compared areas.
Possible outcome of the analysis
An illustrated report may support exclusion, source attribution or an inconclusive result; certainty depends on surviving detail and comparison materials.
Limits of the conclusions
Width alone does not individualise a tool. The mark cannot by itself establish a person, contact time or purpose; subsequent use may alter the edge.