July 28, 2026
DUI Defense Evidence Checklist for Maryland Cases
A DUI arrest can feel decided before you have had a chance to explain what happened. It is not. A careful DUI defense evidence checklist can help identify what exists, what may disappear, and what needs closer review before decisions are made about court, a license hearing, or a plea.
For Maryland drivers, the details matter. A traffic stop may begin with a claimed lane violation, a broken light, speeding, or an officer’s concern about impairment. Each part of that sequence can be tested against records, video, witness accounts, and the rules that apply to DUI and DWI investigations. The goal is not to guess at a defense from a police report. It is to preserve the facts and evaluate them carefully.
Start Preserving Evidence Right Away
Some of the most useful evidence is not held by the driver. Police body-worn camera footage, dash camera video, 911 recordings, dispatch logs, and nearby business surveillance may be retained only for a limited time. A lawyer can take steps to request or preserve materials that may matter to the case.
Your own memory also changes quickly. As soon as you are able, write down a private timeline of the evening: where you were, what you ate or drank, when you last slept, any medications you took, the weather, your route, the reason for the stop, and everything you remember being asked to do. Include exact words when you can remember them, but do not fill gaps with assumptions.
Save receipts, parking records, rideshare records, text messages, and photos that establish timing or location. If someone was with you before, during, or after the stop, keep their contact information. Do not ask anyone to change a story, remove posts, or hide evidence. Preserving facts is appropriate. Altering or destroying evidence can create a separate and serious problem.
DUI Defense Evidence Checklist: The Traffic Stop
A DUI case often turns first on why the officer stopped the vehicle. Officers need a legally valid basis for a traffic stop, although that basis can be a minor traffic infraction. The police report may state one reason, while video or vehicle records may show a more complete picture.
Review whether the following evidence is available:
- The officer’s report, citations, and any statement of probable cause
- Dash camera and body camera footage from the officer and other responding officers
- Dispatch, 911, and computer-aided dispatch records showing the timing and reason for the call or stop
- Photos or video of the roadway, traffic signs, lighting, lane markings, and weather conditions
- Vehicle records or repair documentation if the stop involved an alleged equipment issue
A claim that a driver crossed a line, failed to signal, or had a defective light is not automatically wrong or automatically enough to end the inquiry. Video quality, camera angle, road design, and the precise timing of the officer’s observations can all matter. In some cases, the stop is well supported. In others, the evidence raises questions worth addressing through the legal process.
What Happened Outside the Vehicle
Once a driver is out of the vehicle, officers commonly look for signs of impairment and may request field sobriety tests. These tests are often presented as objective, but the conditions under which they are performed deserve close attention.
Field sobriety testing can be affected by uneven pavement, rain, poor lighting, traffic, footwear, a medical condition, injury, fatigue, age, or instructions that were difficult to hear or understand. Body camera footage may show conditions that a written report barely mentions. It can also show whether instructions were given consistently and whether a driver’s performance matched the officer’s description.
Medical records can be relevant when a documented condition affects balance, coordination, speech, or eye movement. So can information about prescription medication, though medication issues require careful legal and factual review. Never stop or change prescribed medication because of a criminal case without speaking with your medical provider.
Witnesses may also help clarify what occurred. A passenger, a person who spoke with you shortly before the stop, or someone who observed the arrest may have useful information. Their value depends on what they actually saw and how clearly they can describe it.
Chemical Testing Requires More Than a Number
A breath or blood result is important evidence, but it is not the entire case. Test results have a timeline, a method, paperwork, equipment records, and chain-of-custody questions behind them.
For a breath test, an attorney may review the testing printout, observation period documentation, the sequence of tests, and records related to the instrument’s maintenance and accuracy checks. The timing of the test matters because alcohol concentration can change between driving and testing. Issues such as mouth alcohol, recent consumption, certain medical conditions, or a failure to follow required procedures may also require evaluation.
For a blood test, the focus may include the warrant or consent issues, who drew the blood, how the sample was labeled and stored, laboratory procedures, and the chain of custody. A gap or inconsistency in documentation does not always invalidate a result, but it should not be ignored.
Maryland cases can also involve an allegation of driving while impaired by drugs. In those cases, evidence may include officer observations, statements, laboratory testing, medication history, and the opinion of a drug recognition expert. These cases are especially fact-specific. A positive result does not always answer the separate question of impairment at the time of driving.
Statements, Timing, and Police Paperwork
People often remember a DUI arrest in fragments. That is understandable. Still, the timing of statements can be highly important. The prosecution may rely on comments about drinking, where you were coming from, medical issues, or a refusal to take a test. Your lawyer should review what was said, when it was said, and whether it was accurately recorded.
Compare the police report with video, dispatch records, test documentation, and your own timeline. Small discrepancies are not automatically case-changing. But when the report says one thing and objective evidence shows another, that difference may affect credibility, procedure, or the weight a court gives the evidence.
It is also wise to keep every document you received after the arrest. Maryland DUI and DWI charges can trigger both criminal court obligations and Motor Vehicle Administration consequences. The paperwork may include deadlines or options that should be reviewed promptly. Waiting can limit choices, even if you have a strong concern about the arrest itself.
What Not to Do While Your Case Is Pending
A useful evidence checklist also includes avoiding mistakes that make a difficult situation harder. Do not discuss the facts of the arrest on social media. Posts, photos, messages, and comments can be misunderstood or used out of context. Do not contact the arresting officer, potential witnesses, or other involved parties to argue the case.
Do not assume a charge will disappear because you believe the officer was unfair. At the same time, do not assume a breath result or a difficult roadside encounter means there is nothing to review. A practical defense begins with the actual evidence, not fear or false reassurance.
Follow all court dates, release conditions, and licensing instructions. If you are unsure what a document requires, ask questions early. A missed hearing or deadline can create consequences that are avoidable with prompt attention.
Bring the Right Materials to Your Consultation
When you speak with a DUI defense attorney, bring or send the citation, charging documents, notice from the MVA, bail or release paperwork, towing documents, and any test results you received. Share your written timeline, witness information, relevant medical information, and records that establish where you were before the stop.
You do not need to organize every detail perfectly before seeking help. In fact, early legal guidance can help determine which records should be pursued first. At Montero Law Group, clients can discuss the circumstances of a Maryland DUI or DWI arrest in clear, practical terms and get guidance on the next steps.
The best time to begin protecting evidence is before memories fade and recordings are overwritten. Save what you have, avoid creating new problems, and get experienced advice that fits the facts of your case.