Can counsel use evidence of an expert witness’s professional disciplinary history to challenge the expert’s credibility?

The Indiana Supreme Court in Tunstall v. Manning, No. 195-CT-18 (Indiana Sup. Ct. June 26, 2019), said a limited yes. The Supreme Court held that the defendant in a personal injury action should have been able to introduce evidence of past professional discipline against plaintiff’s expert, but not evidence of the misconduct that led to the discipline. Because it found that the trial court’s exclusion of the licensure evidence was harmless error, the Supreme Court upheld a $1.3 million jury verdict.

The plaintiff, Manning, sued defendant Tunstall after suffering a neck injury in a car accident. Dr. Steven Paschall, the physician who treated Manning after the accident, testified on her behalf. Dr. Paschall was asked about his disciplinary history during his deposition. While he admitted that his medical license had previously been on probation, he refused to answer questions about the reasons for this discipline. The trial court denied a motion to compel Dr. Paschall to answer those questions, holding that evidence about past licensure probation was irrelevant given that Dr. Paschall’s license was in good standing at the time of trial. The Supreme Court disagreed:

Evidence of the licensure probation was admissible to impeach the doctor because it was relevant to his credibility and its probative value outweighed any prejudicial effect. See Evid. R. 401, 402, 403.

Still, relevant evidence must pass Indiana Evidence Rule 403’s balancing test. Sims v. Pappas, 73 N.E.3d 700, 707 (Ind. 2017). Under Rule 403, a court may exclude relevant evidence “if its probative value is substantially outweighed by a danger of . . . unfair prejudice, confusing the issues, misleading the jury, undue delay, or needlessly presenting cumulative evidence.” Evid. R. 403.

Here, the probative value of the licensure-probation evidence outweighed any of Rule 403’s dangers. Dr. Paschall was the only medical expert to testify on Manning’s behalf, and his medical license was placed on probation only a few months after he first examined Manning.

Thus, the trial court should not have excluded this evidence. The jurors were entitled to hear it and assess whether it affected their view of the doctor’s expert testimony.

As to the evidence regarding the reasons for the doctor’s past professional discipline, the Supreme Court found that it was relevant for impeachment purposes but was inadmissible under specific evidentiary rules. It explained:

Tunstall also tried to impeach Dr. Paschall’s testimony with evidence of the reasons for his professional discipline. These reasons included two prior misdemeanor convictions and two other acts of misconduct. Because this evidence was inadmissible for impeachment under certain evidentiary rules, the trial court properly excluded it.

The court went on to uphold the jury verdict.

We hold that an expert witness’s professional licensure status and the reasons for professional discipline may be admissible to impeach that expert’s credibility. The trial court abused its discretion here by excluding evidence that Dr. Paschall’s medical license had previously been on probation. But because we find that error was harmless, we affirm the jury’s verdict.