Supply Chain Tracing
Definition
In Koehler's investigation, the process of tracking the ladder lumber from the sawmill of origin through the distribution network to the retail yard where it was purchased, using mill marks, grade stamps, species identification, and planer records.
- Case
- Lindbergh kidnapping, Koehler investigation
- Evidence traced
- Ladder lumber
- Method used
- Mill marks, grade stamps, species ID, planer records
- Endpoint
- Sawmill of origin to retail purchase point
Common questions
What made the ladder timber traceable back through the supply chain in the Koehler investigation?+
Arthur Koehler identified the wood species and matched distinctive planer marks left by a specific machine's blade defects, then cross-referenced planing mill shipping records to narrow down which lumber yards had received that batch. The combination of physical tool marks and paper trail records let him work backward from the ladder to a specific retail source.
Why is this considered an early landmark case for forensic wood examination?+
It demonstrated that individual machining tools leave reproducible, source-specific marks on lumber, similar in principle to tool mark evidence on metal, and that combining this with commercial distribution records could trace an object to a specific purchase. The approach helped establish wood and tool mark analysis as credible trial evidence in the United States.
Related terms
- Crossgrain
- A condition in which the wood fibres run at an angle to the long axis of the piece. In Rail 16, Koehler...
- Grain Matching
- The physical comparison of growth-ring pattern and fibre direction at a fracture or cut surface to an adjacent piece of wood. Because...
- Plane Mark
- A surface trace left by a hand or machine plane, showing the arc of the blade stroke and any irregularities such as...
- Rail 16
- Koehler's designation for the left side rail of the bottom section of the Lindbergh ladder. The rail that was matched by grain,...
- Tool-Mark Analysis (Wood)
- Examination of surface marks left by cutting, planing, or shaping tools to identify the tool type, size, and individual characteristics of the...