Zachary Marshall’s Approach to DUI Case Evaluations: Precision, Structure, and Attorney-Ready Analysis
Overview
A DUI investigation is only as strong as the procedures behind it. Zachary Marshall’s approach to case evaluation is built on a simple principle: every step of the investigation must meet the standards required for reliability, clarity, and courtroom defensibility.
As a former Washington law enforcement officer and now a DUI and collision-analysis consultant based in Arlington, WA, Zachary applies a rigorous technical framework designed specifically for defense attorneys.
His evaluations dissect the investigation through a methodical lens, identifying whether the evidence aligns with NHTSA protocols, state administrative requirements, and the scientific principles underpinning impaired-driving detection.
Defense attorneys across Snohomish County, the Seattle Metropolitan area, the West Coast, and nationwide rely on Zachary’s structured analysis for negotiation leverage, suppression motions, and trial preparation.
The Foundation of a Strong Evaluation
Zachary’s process is grounded in technical accuracy, documented standards, and neutral examination of the facts.
He analyzes each case with a consistent, attorney-focused structure:
Vehicle in Motion analysis (NHTA-validated driving indicators, LE procedures, and predictive reliability)
Personal Contact assessment (articulation, sensory observations, timing, and environment)
SFST administration & scoring accuracy
Bodycam/dashcam evidence comparison
Report-writing consistency
Probable cause development & timeline reconstruction
Breath-test procedural integrity
Toxicology interpretation
Crash mechanics and impairment interplay
DOL/DMV administrative considerations
This approach allows defense counsel to see exactly how the investigation unfolded, and where it did not meet required standards.
SFST & NHTSA Compliance
Standardized Field Sobriety Tests are intended to be administered and interpreted according to strict, nationally recognized protocols.
Zachary evaluates:
Correctness of instructions
Demonstration quality
Environmental factors
Clue interpretation
Scoring accuracy
Comprehension checks
Divided-attention conflict factors
Camera-to-report discrepancies
Small deviations often have significant impact on reliability. Zachary’s evaluations highlight each of these breakpoints with precise, citation-supported analysis.
Breath-Test Protocol Integrity
Breath-test evidence hinges on proper compliance with observation periods, equipment handling, and adherence to state protocols.
Zachary reviews:
15-minute observation period accuracy
Timing and sequencing
Instrument usage and deviations
Physiological factors affecting results
Environmental contamination risks
Draeger-specific procedural issues
His reviews allow attorneys to clearly identify whether the results remain procedurally defensible, or whether they create challengeable grounds.
Bodycam/Dashcam Discrepancy Analysis
Video evidence is one of the strongest tools in DUI litigation, but only when it is examined carefully.
Zachary performs structured video reviews that compare officer articulation with:
Observable behavior
SFST performance
Sequence of events
Timeline gaps
Evidence handling
Officer decision-making
This analysis often uncovers subtle but critical inconsistencies that influence credibility and probable cause.
Collision & Personal Injury Integration
Many DUI cases involve crashes, and Personal Injury (PI) attorneys regularly face collision reports that rely heavily on officer interpretation.
Zachary provides:
Pre-impact vehicle dynamics review
Causation vs. correlation distinction
Scene and roadway-condition analysis
Driver behavior and avoidance opportunity evaluation
Investigative methodology critique
Alignment of crash mechanics with impairment claims
Whether part of a vehicular criminal case or a civil personal injury matter, this analysis clarifies the relationship between impairment evidence and actual crash causation.
Administrative Hearing (DOL/DMV) Strategy
Zachary prepares DOL/DMV-oriented technical evaluations that address:
Timeline inconsistencies
Officer articulation issues
Breath-test procedural gaps
Documentation errors
Foundational weaknesses
These reviews help attorneys approach administrative hearings with structured, targeted challenges.
Neutral, Technical, Defense-Facing Insight
Zachary’s evaluations are not advocacy. They are technical assessments that reveal what the evidence actually supports.
Defense attorneys use his work to:
Strengthen negotiation posture
Prepare cross-examination
Formulate suppression arguments
Clarify expert strategy
Build trial themes
His structure ensures every evaluation is clear, organized, and courtroom-ready.
Contact
For a structured DUI case evaluation or collision-related review, contact:
Zachary Marshall
Founder & Lead Consultant - Legal Limit Consulting, LLC
Arlington, Washington
Phone: (425) 224-5149
Email: Z.Marshall@LegalLimitConsulting.com
Website: www.LegalLimitConsulting.com
