What Is the Burden of Proof?
The burden of proof is the legal obligation to prove your claims in court with sufficient evidence. In a personal injury case, the burden of proof falls on the plaintiff — the person who was injured and is seeking compensation. If you cannot meet the burden of proof, your case will fail, regardless of how serious your injuries are.
In the American legal system, different types of cases require different levels of proof. Criminal cases require proof “beyond a reasonable doubt” — the highest standard. Civil cases, including personal injury claims, use a lower standard called “preponderance of the evidence.” Understanding this distinction is critical if you are pursuing a personal injury claim in Oklahoma.
At Hasbrook & Hasbrook, we build every case with the burden of proof in mind from day one. Every piece of evidence we gather, every expert we consult, and every argument we make is designed to meet — and exceed — the legal standard required to win your case.
What Does Preponderance of the Evidence Mean?
Preponderance of the evidence means that your version of events is more likely true than not — essentially, that there is a greater than 50% chance your claims are accurate. This is the standard used in virtually all personal injury cases in Oklahoma.
Think of it as tipping a scale. You do not need to prove your case with absolute certainty. You need to show that the weight of the evidence favors your version of events, even slightly. If a jury believes there is a 51% likelihood that the defendant caused your injuries, you have met your burden.
This is a significantly lower bar than the “beyond a reasonable doubt” standard in criminal cases. That said, “lower” does not mean “easy.” Insurance companies and defense attorneys aggressively challenge evidence, dispute medical records, and hire experts to undermine your claims. A strong case with thorough documentation is essential.
How Is Burden of Proof Different in Civil vs. Criminal Cases?
The fundamental difference is the standard: civil cases require “preponderance of the evidence” (more likely than not), while criminal cases require proof “beyond a reasonable doubt” (near certainty). This means it is possible for a defendant to be found not guilty in a criminal case but still be held liable in a civil lawsuit arising from the same incident.
| Factor | Civil Case (Personal Injury) | Criminal Case |
|---|---|---|
| Standard of Proof | Preponderance of the evidence (~51%+) | Beyond a reasonable doubt (~95%+) |
| Who Has the Burden | Plaintiff (injured person) | Prosecution (the state) |
| What Must Be Proved | Defendant’s negligence caused harm and damages | Defendant committed a crime |
| Possible Outcomes | Liable / Not liable — monetary damages awarded | Guilty / Not guilty — fines, prison, probation |
| Jury Verdict | Majority or 3/4 agreement (varies by state) | Unanimous |
| Example | Car accident victim sues negligent driver for medical bills and lost wages | State prosecutes drunk driver for vehicular assault |
A well-known example of this distinction is the O.J. Simpson case: Simpson was acquitted in the criminal trial but found liable in the subsequent civil wrongful death lawsuit. The same evidence met the civil standard but did not meet the criminal one.
Who Has the Burden of Proof in a Personal Injury Lawsuit?
The plaintiff — the person who was injured — carries the burden of proof in a personal injury lawsuit. This means it is your responsibility to prove that the defendant acted negligently, that the negligence caused your injuries, and that you suffered actual damages as a result.
The defendant does not have to prove they are innocent. They only need to raise enough doubt about your evidence to prevent you from meeting the preponderance standard. In practice, defense attorneys and insurance companies focus on poking holes in your evidence: questioning whether your injuries are as serious as claimed, whether the defendant’s actions actually caused the accident, or whether you share some of the fault.
This is why thorough documentation from the very beginning of your case is so important. Medical records, police reports, witness statements, photographs, and expert opinions all serve as building blocks for meeting your burden of proof.
What Evidence Do You Need to Meet the Burden of Proof?
To meet the burden of proof in an Oklahoma personal injury case, you need documentary evidence, testimonial evidence, physical evidence, and often expert testimony that together demonstrate the defendant’s negligence caused your injuries and damages.
| Evidence Type | Description | Examples |
|---|---|---|
| Documentary | Written or recorded materials that establish facts | Medical records, police reports, billing statements, insurance correspondence, employment records |
| Testimonial | Statements from witnesses who observed relevant events | Eyewitness accounts, your own testimony, statements from family about how injuries affect daily life |
| Physical | Tangible objects or visual evidence from the incident | Photographs of the accident scene, vehicle damage, visible injuries, surveillance or dashcam footage |
| Expert | Professional opinions from qualified specialists | Accident reconstruction experts, medical experts linking injuries to the accident, economists calculating future damages |
| Digital | Electronic data that corroborates or contradicts claims | Cell phone records, GPS data, vehicle black box (EDR) data, social media posts |
No single piece of evidence wins a case. The strength of a personal injury claim comes from how well different types of evidence corroborate each other. A police report that confirms the defendant ran a red light, combined with medical records showing injuries consistent with the collision, combined with an eyewitness account — that is a case that clearly meets the preponderance standard.
What Is the Burden of Proof for Negligence in Oklahoma?
To prove negligence in Oklahoma, you must establish four elements by a preponderance of the evidence: duty, breach, causation, and damages. If you fail to prove any one of these elements, your negligence claim fails.
| Element | What You Must Prove | Example (Car Accident) |
|---|---|---|
| 1. Duty of Care | The defendant owed you a legal duty to act with reasonable care | All drivers have a duty to follow traffic laws and drive safely |
| 2. Breach of Duty | The defendant violated that duty through action or inaction | The defendant ran a red light, was texting while driving, or was speeding |
| 3. Causation | The breach directly caused your injuries (both actual and proximate cause) | Running the red light caused the collision that fractured your spine |
| 4. Damages | You suffered actual, measurable harm as a result | $85,000 in medical bills, $30,000 in lost wages, ongoing pain and suffering |
Oklahoma courts apply the “reasonable person” standard when evaluating duty and breach. The question is: would a reasonable person in the defendant’s position have acted the same way? If not, the defendant breached their duty. Under 23 O.S. § 13, the measure of damages in personal injury cases includes compensation for detriment proximately caused by the defendant’s wrongful act, whether that detriment could have been anticipated or not.
How Do Statutes of Limitations Affect Your Burden of Proof?
Oklahoma’s statute of limitations gives you a strict deadline to file your lawsuit — and if you miss it, you lose the right to pursue your claim entirely, regardless of how strong your evidence is.
Under 12 O.S. § 95, the general statute of limitations for personal injury cases in Oklahoma is two years from the date of the injury. This applies to car accidents, slip-and-fall injuries, medical malpractice, and most other personal injury claims.
But the statute of limitations does more than set a deadline. It also affects the quality of your evidence. The longer you wait to pursue a claim, the more your evidence deteriorates: witnesses forget details, surveillance footage gets deleted, medical records become harder to connect to the original incident, and physical evidence from the scene may be lost.
There are limited exceptions to the two-year rule. For claims against government entities under the Oklahoma Governmental Tort Claims Act (51 O.S. § 156), you must file a written tort claim notice within one year of the incident — before you can even file a lawsuit. Missing this notice deadline is fatal to your claim.
The discovery rule may extend the deadline in cases where the injury was not immediately apparent, but these exceptions are narrow and fact-specific. The safest approach is to contact an attorney as soon as possible after your injury.
What Role Does Expert Testimony Play in Meeting the Burden of Proof?
Expert testimony often makes the difference between winning and losing a personal injury case because experts can explain complex medical, technical, or financial issues that are beyond the average juror’s experience.
In many Oklahoma personal injury cases, the facts are not in dispute — what is in dispute is what those facts mean. Did the plaintiff’s injuries result from the accident or from a pre-existing condition? How much will future medical care cost? Was the defendant’s driving below the standard of care? These questions require expert analysis.
Common types of expert witnesses in Oklahoma personal injury cases include:
- Medical experts — Physicians who testify about the nature, cause, and prognosis of your injuries, the treatment you need, and whether your injuries are consistent with the accident
- Accident reconstruction experts — Engineers who analyze physical evidence to determine how the accident occurred, vehicle speeds, and points of impact
- Economic experts — Economists or vocational rehabilitation specialists who calculate lost earning capacity, future medical expenses, and the present value of long-term damages
- Life care planners — Specialists who project the cost of future medical care, assistive devices, and support services for catastrophic injuries
Oklahoma follows the Daubert standard for admissibility of expert testimony. The trial court acts as a gatekeeper, ensuring that expert opinions are based on reliable methods and relevant to the case. Your attorney’s ability to retain credible experts and present their testimony effectively can be the deciding factor in meeting the burden of proof.
Can Comparative Negligence Affect the Burden of Proof?
Yes — Oklahoma’s modified comparative negligence rule (51% bar) means the defendant can shift part of the burden back to you by arguing that you share fault for the accident. If the jury finds you are 51% or more at fault, you recover nothing.
Under Oklahoma’s comparative negligence statute, the defendant is not limited to simply denying your claims. They can affirmatively argue that your own negligence contributed to the accident. Common examples include:
- Arguing you were speeding or distracted at the time of the collision
- Claiming you failed to wear a seatbelt (which can reduce damages in Oklahoma)
- Alleging you ignored medical advice, worsening your injuries
- Asserting you were partially at fault for a slip-and-fall by ignoring warning signs
If the jury assigns you a percentage of fault, your damages are reduced by that percentage. For example, if your total damages are $200,000 and the jury finds you 30% at fault, you recover $140,000. But if they find you 51% or more at fault, you recover $0.
This is why the burden of proof in Oklahoma personal injury cases is a two-way street. You must prove the defendant’s negligence, and you must be prepared to defend against claims that you contributed to the accident. Strong evidence that minimizes your share of fault — dashcam footage, witness testimony, toxicology results — is essential.
How Can an Oklahoma Personal Injury Lawyer Help You Meet the Burden of Proof?
An experienced Oklahoma personal injury lawyer helps you meet the burden of proof by investigating the accident, gathering and preserving evidence, retaining qualified experts, and building a case narrative that clearly establishes each element of negligence.
Meeting the burden of proof is not something that happens at trial — it starts from the moment you hire an attorney. Here is how an experienced personal injury lawyer builds a case that meets the standard:
- Immediate investigation — Securing physical evidence, obtaining police reports, interviewing witnesses, and preserving surveillance footage before it is lost or destroyed
- Medical documentation — Ensuring you receive proper medical care and that your treatment records clearly link your injuries to the accident
- Expert retention — Identifying and hiring medical, engineering, economic, and vocational experts whose testimony strengthens each element of your claim
- Discovery and depositions — Using the legal discovery process to compel the defendant and insurance company to produce documents, answer questions, and provide sworn testimony
- Damage calculation — Working with economists and medical professionals to calculate the full extent of your damages, including future losses under 23 O.S. § 13
- Trial preparation — Organizing evidence, preparing witness testimony, and crafting arguments that present a clear, compelling narrative for the jury
At Hasbrook & Hasbrook, we understand that the burden of proof is not just a legal concept — it is the foundation of every personal injury case. We do not take shortcuts, and we do not leave critical evidence on the table. Our goal is to build a case so strong that the defendant’s insurance company knows it will lose at trial, which gives us maximum leverage in settlement negotiations.
What Oklahoma Statutes Govern Personal Injury Burden of Proof?
Three Oklahoma statutes are particularly important to the burden of proof in personal injury cases: the measure of damages statute (23 O.S. § 13), the statute of limitations (12 O.S. § 95), and the governmental tort claims notice requirement (51 O.S. § 156).
- 23 O.S. § 13 — Measure of Damages: This statute establishes that a person injured by the wrongful act of another is entitled to recover compensation for “detriment proximately caused thereby.” This defines what you must prove to recover damages and the scope of recoverable losses. Oklahoma is a “paid, not incurred” state, meaning you can recover only medical expenses actually paid or owed — not the full billed amount.
- 12 O.S. § 95 — Statute of Limitations: This statute sets the two-year filing deadline for personal injury lawsuits. Filing after the deadline permanently bars your claim. The clock typically starts on the date of injury, though the discovery rule may apply in limited circumstances.
- 51 O.S. § 156 — Governmental Tort Claims Notice: If your injury was caused by a state or local government entity or employee, this statute requires you to file a written tort claim notice within one year of the loss. This is a prerequisite to filing a lawsuit and failure to comply is an absolute bar to recovery.
These statutes interact with each other. For example, even if you have strong evidence that meets the preponderance standard, failing to comply with the notice requirements under 51 O.S. § 156 or the filing deadline under 12 O.S. § 95 will prevent you from ever presenting that evidence to a jury. This is why early legal consultation is critical.
How Can You Get Help With Your Personal Injury Claim Today?
You can get help with your personal injury claim today by calling Hasbrook & Hasbrook at (405) 605-2426 or visiting our contact page to schedule a free, no-obligation consultation.
Understanding the burden of proof is important, but you do not have to carry that burden alone. Our Oklahoma personal injury attorneys have spent decades building cases that meet and exceed the legal standard — and we have the track record to prove it.
When you call us, here is what happens:
- Free case review — We listen to what happened, review any evidence you have, and give you an honest assessment of your case
- No upfront cost — We work on a contingency fee basis. You pay nothing unless we recover compensation for you
- Immediate action — If we take your case, we begin investigating and preserving evidence right away
The statute of limitations is running. Evidence is deteriorating. Insurance companies are building their defense. Do not wait to get the legal help you need.
Call (405) 605-2426 now for a free consultation, or contact us online.
Hasbrook & Hasbrook — Oklahoma City Personal Injury Lawyers
