Writing a DUI arrest report

A DUI report is read by a prosecutor deciding whether the case can be made, and by a defense attorney looking for the link in the chain that was never written down.

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The chain the report has to complete

A DUI report documents a sequence, and each step has to support the next. Reasonable suspicion for the stop. Observations on contact. The decision to investigate impairment. The field sobriety tests and what they showed. Probable cause for the arrest. Then the chemical test and its handling.

A break anywhere in that chain is where the case is attacked. Most breaks are not conduct failures — they are steps the officer took and did not record.

The reason for the stop is a separate finding

The stop needs its own justification, independent of anything found afterward. Weaving within a lane is not automatically sufficient in every jurisdiction; crossing the center line twice over a measured distance usually is.

State what was observed, where, and for how long. "Driving erratically" is not a basis a court can review.

Weaker

“I observed the vehicle driving erratically and initiated a traffic stop.”

Stronger

“I observed the vehicle cross the center line twice over approximately a quarter mile on N Rockford Road, the second time with the driver-side tires fully in the oncoming lane for roughly two seconds.”

The first cannot be evaluated. The second can be measured against the standard in your jurisdiction.

Observations on contact

Record the specific indicators, not the conclusion drawn from them. Odor of an alcoholic beverage and its strength. Speech. Eyes. Coordination handling documents. Statements the driver made about drinking, quoted where possible.

If an indicator was absent, that is worth recording too. A report listing every classic sign and no absences reads as a form filled in rather than an observation made.

Field sobriety tests

Note that conditions were suitable, or why they were not — surface, lighting, footwear, traffic, weather. Record the instructions given and that the subject said they understood. Record the specific clues observed on each test, not a pass or fail.

Any medical condition, injury or language barrier the subject raised must appear, along with what was done about it.

Reason for the stop stated as an observation with location and duration
Specific impairment indicators recorded, and notable absences
Conditions for field sobriety testing described
Clues observed per test, rather than a conclusion
Any medical condition or language barrier raised, and the response
Miranda timing recorded, if applicable in your jurisdiction
Chemical test, operator, instrument and time recorded
Chain of custody unbroken and documented

Narrative AI runs these checks automatically. Its pre-submission audit reads the report before it is filed and flags the gaps above — vague force language, justification that was never articulated, timelines that do not match CAD — while the officer can still fix them.

How the pre-submission audit works →

This guide is general and is not legal advice. Standards differ by state and by agency policy; where they conflict with anything here, your policy and your prosecutor govern.