Precision in the details. Clarity in the conclusions.
Zachary Marshall is a certified Drug Recognition Expert and advanced collision investigator with a career in municipal law enforcement, now retained nationwide to evaluate impaired driving and vehicular crime matters where the technical record decides the case.
During that career, he conducted hundreds of DUI investigations, served as lead investigator on serious-injury and fatal collisions, and operated the FARO 3D scene documentation technology in the field, experience that informs his current causation and evidentiary analysis. The same standards used to build the State's case are now applied independently to assess where it does, and does not, hold up.
Training behind the analysis.
- Drug Recognition Expert (DRE)
- Advanced Roadside Impaired Driving Enforcement (ARIDE)
- IPTM At-Scene Traffic Crash/Traffic Homicide Investigation
- IPTM Advanced Traffic Crash Investigation, Advanced Coursework
- FARO 3D Laser Scanning Technology
- FARO Zone 3D & FARO Scene
- Preliminary Breath Test (PBT), Intoximeter Alco-Sensor FST Technician
- Evidentiary Breath Test Operator, Dräger
- FBI Certified Hostage & Crisis Negotiator
Recognized for excellence in impaired-driving enforcement and investigation.
Recognition earned through DUI enforcement, traffic investigation, and related public-safety work, experience now applied through independent expert analysis for the defense.
- Two-Time Officer of the Year, Washington Target Zero Program
- Commendation, Mothers Against Drunk Driving (MADD)
- Commendation, U.S. Drug Enforcement Administration (DEA)
- Two-Time DUI Enforcement Award Recipient, Chief of Police
- Founding Member, Dedicated Municipal Traffic Unit
Technical analysis, translated for litigation.
Every engagement begins with a candid conversation. Where the record is strong for the State, it is named plainly. Where there is leverage, it is identified, documented, and translated into something usable: a written strategic report, cross-examination outlines, motion support, or trial testimony.
The practice is intentionally limited. Engagements are limited each quarter so that every matter receives the attention serious cases require. Adjacent expertise, including FBI-certified crisis negotiation and ongoing law enforcement subject-matter consulting for AI development, informs the work without diluting its focus.
- DUI Defense Lawyers Association (DUIDLA)/
- California DUI Lawyers Association (CDLA)/
- Washington Association of Criminal Defense Lawyers (WACDL)/
- Washington Defenders Association (WDA)