Fig 1 — Evidence examination at a crime scene. Photo by Pexels.
Three decades in forensic chemistry and GIS-driven crime analysis. Formerly with county lab operations, now independent — consulting on evidence handling protocols, training new officers in chain-of-custody discipline, and running a small garden that keeps me grounded when the caseload gets heavy.
My work lives at the intersection of procedure and public trust. Every protocol I've helped write exists to ensure one thing: when evidence moves from scene to lab to courtroom, nothing is lost along the way.
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The Thermal Handshake
When evidence arrives at the lab, it enters a phase I call the thermal handshake — the period during which the sample's environment equalizes with the evidence room. This is the most critical window in chain-of-custody. A sample arriving from a 95°F scene into a 65°F lab will begin condensing within ninety minutes if not acclimated properly. Those micro-droplets can dissolve trace powders, alter pH readings, and compromise fiber samples.
"The chain of custody is not just paper. It is the physical state of the sample at every handoff. If you lose the thermal record, you lose the case."
⚠ Critical Note
Evidence arriving from humid environments (>70% RH) must be placed in a staging locker at 55°F before entering the main evidence room. Skipping this step is the single most common cause of contamination I've seen in twenty years of audits.
Scene-to-Lab: The Seven-Point Handoff
Every sample leaving the scene must pass through this checklist. I've carried this list in my pocket since 1994. It has never failed.
Container integrity verified — tamper seal intact, serial number logged
Ambient conditions recorded at pickup — temperature, RH, light exposure
Sample identity confirmed twice — collector and receiving analyst both read label aloud
Chain-of-custody form signed at every handoff — no initials, full name, time, date
Transport container checked for temperature drift — log shows no excursion >2°F
Receiving analyst signs intake within four hours of arrival
Sample placed in designated storage zone — photographed in situ within 24 hours
Connected Work
The work of evidence handling doesn't exist in isolation. It connects to broader questions of justice, infrastructure, and community trust. Two neighbors whose work resonates with mine:
