Expert Witness
Specialists who testify about police training, use of force, or medical injuries — expensive but sometimes essential.
What It Is
An expert witness is someone with specialized knowledge who can testify about matters beyond ordinary understanding. In § 1983 cases, experts are commonly used for:
- Use-of-force standards — Retired police trainers who testify about whether the force was consistent with accepted practices
- Police practices — Experts on department policies, training adequacy, and industry standards
- Medical/psychological — Doctors who testify about injuries, PTSD, or the medical effects of the violation
- Economics — Experts who calculate lost wages and future economic harm
Do You Need One?
Not always. § 1983 claims can succeed without expert testimony — especially when video evidence speaks for itself or the facts clearly establish the violation. But experts help when:
- The use of force is borderline and you need someone to explain why it was unreasonable
- You’re claiming failure to train and need someone to identify training deficiencies
- Your damages include complex economic losses
- The defense will have their own expert (and usually they will)
The Daubert Standard
Under Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 579 (1993) and Federal Rule of Evidence 702, expert testimony must be:
- Based on sufficient facts or data
- The product of reliable principles and methods
- Reliably applied to the facts of the case
The court acts as gatekeeper. Defendants will try to exclude your expert under Daubert.
The Pro Se Problem
Expert witnesses are expensive — $200-$500/hour for review and testimony, sometimes more. For pro se litigants proceeding IFP, this is often prohibitive.
Options:
- Volunteer experts — Some retired officers or academics will review cases pro bono
- Organizations — Groups like NPAP may help connect you with experts
- Declarations instead of live testimony — Written expert declarations are cheaper than bringing someone to trial
- Argue you don’t need one — For clear-cut excessive force cases, the video is your expert
Key Rules
- Rule 26(a)(2) — Expert witness disclosure requirements
- Rule 702 — Expert testimony admissibility
- Daubert v. Merrell Dow — Reliability standard for expert opinions