What Evidence to Gather After an Accident: A Checklist That Protects Your Claim

After a crash, the clock starts immediately — and so does the other side. Insurance adjusters begin to immediately build a case that pays you as little as possible. Meanwhile, the evidence that proves what really happened starts disappearing on its own. Skid marks fade. Surveillance footage gets recorded over. A damaged car gets repaired, and the data inside it vanishes with it.

Here’s the hard truth: in a dispute over who’s at fault, the person with better evidence usually wins. Memories are easy to attack. A timestamped photo, a witness’s name, or a black-box readout is not. Both Nevada and California decide cases on comparative fault — your compensation shrinks by your share of the blame, and in Nevada you recover nothing if you’re found 51% or more at fault. Evidence is what moves that percentage in your favor.

This is the evidence to gather, why it matters, and exactly how to protect it.

Start at the Scene: Photos & Video

Your phone is your most powerful tool in the first minutes. Photograph everything, from wide shots to close-ups: vehicle damage on every car, license plates, the position of vehicles before they’re moved, skid marks, debris, traffic signals, road conditions, weather, and your visible injuries. Then shoot slow video panning across the whole scene; video captures context still photos often miss.

Takeaway: Take far more than you think you need. You can’t go back tomorrow; the scene will be gone.

The Digital Witnesses: Dash Cam, Black Box, and App Data

This is where modern cases are won — and where evidence vanishes fastest.

Dash cam footage is often the single most persuasive piece of evidence because it’s neutral and unblinking. If you have a dash cam, save and back up the file immediately so it isn’t overwritten.

Black box (EDR) data lives inside almost every modern vehicle. According to the National Highway Traffic Safety Administration, an Event Data Recorder captures technical data in the seconds before, during, and after a crash, and under federal standards (49 CFR Part 563), recorded EDRs must log a core set of elements such as speed, braking, throttle, steering input, seat belt use, and airbag deployment. That data can flatly contradict a driver who claims they were slowing down when they were actually accelerating. The catch: many EDRs store only a short window; data can be overwritten once the vehicle is driven again or lost entirely when the car is repaired or scrapped.

GPS and app data — from your phone, your vehicle’s connected services, or a rideshare app — can establish location, speed, and timeline. In an Uber or Lyft crash, the app’s trip record is critical.

Takeaway: This evidence is the most decisive and the most perishable. Don’t let the at-fault driver’s car get repaired before the data is pulled. That’s exactly when a lawyer’s preservation letter matters (more below).

The Official Record: Police & Incident Reports

Always call the police and make sure a report is filed. A police report documents the scene, the parties involved, and often the officer’s initial assessment of fault. For a slip-and-fall or an injury on someone’s property, ask the business or manager to create a written incident report. Get a copy or the report number before you leave.

Takeaway: Get the report number on the spot. “I’ll get it later” too often becomes a report that’s hard to track down.

The People Who Saw It: Witness Information

Independent witnesses are gold because they have no stake in the outcome. Get names, phone numbers, and emails from anyone who saw what happened — before they leave the scene. A neutral bystander’s account can break a “he-said, she-said” tie.

Takeaway: Witnesses scatter within minutes and become nearly impossible to find later. Collect contact info first, statements second.

Your Health Record: Medical Care & a Pain Journal

See a doctor right away — even if you feel fine. Adrenaline masks injuries, and conditions like concussions or soft-tissue damage often surface days later. Prompt treatment does two things: it protects your health and it ties your injuries to the crash, closing the gap insurers love to exploit.

Then keep a pain journal. Write down, day by day, your pain levels, symptoms, sleep, missed work, and the activities you can no longer do. This is some of the only evidence of your “pain and suffering” — the human cost that doesn’t show up on a bill.

Takeaway: Save every medical record, bill, and receipt, and journal consistently. Gaps in treatment are the first thing an adjuster uses to argue you weren’t really hurt.

Why Speed Matters: The Evidence Has an Expiration Date

Much of this evidence destroys itself on a timer. Once a claim is likely, the other side has a legal duty to preserve relevant evidence. When they don’t, courts can impose discovery sanctions in California — including an “adverse inference,” where the jury is told it may assume the destroyed evidence would have hurt the party that lost it. But that protection only kicks in when someone acts fast to demand preservation, usually through a lawyer’s spoliation letter sent before footage is overwritten or a vehicle is repaired.

There’s a second clock, too: the statute of limitations. You generally have two years to file an injury lawsuit in California and two years in Nevada — and claims against government entities can have far shorter deadlines.

Takeaway: The strongest evidence disappears in days, not years. Moving early is the difference between proving your case and arguing it.

Steps to Take Right After an Accident

1. Get safe and call 911. Report injuries and make sure a police report is filed.
2. Photograph and video everything before vehicles are moved, if it’s safe to do so.
3. Collect contact info from all drivers and every witness.
4. Save your digital evidence — back up dash cam footage and note any rideshare trip.
5. See a doctor the same day, and keep every record.
6. Don’t give a recorded statement to the other insurer, and don’t sign anything, until you’ve talked to a lawyer.
7. Call an attorney quickly so preservation letters go out before evidence is erased.

Frequently Asked Questions

Hurt in an Accident? Let Us Protect Your Evidence — and Your Case

Gathering evidence is hard enough when you’re injured and overwhelmed. You shouldn’t have to fight the insurance company and race the clock alone. At Sam & Ash Injury Law, our Las Vegas personal injury attorneys move fast to lock down footage, pull black-box data, track down witnesses, and build the strongest possible case while you focus on healing. Insurers count on you settling cheap out of exhaustion. We don’t let that happen.

Whether your case is worth $15,000 or $1.5 million, you get the same fight. Call us 24/7 for a free, no-obligation consultation: 702-820-1234 (Nevada) or 949-304-2000 (California).

This article is for informational purposes only and does not constitute legal advice. Every case is different; consult a licensed attorney about your specific situation.