The Colorado court, in Etherton v. OWNERS INSURANCE COMPANY, Dist. Court, D. Colorado 2013, dealt with a proposed attempt to impeach an expert witness due to his prior traffic offenses.

The court found that the prior misdemeanor traffic offenses could not be used for impeachment, however, lying about them could be used for impeachment.

The court stated:

Defendant argues that the Court should prohibit plaintiff from impeaching one of its expert witnesses, Dr. Neil Pitzer, with evidence of a driving offense committed in 2007 on the grounds that it is impermissible character evidence and the risk of prejudice outweighs its probative value. Docket No. 76 at 8; see Fed. R. Evid. 403, 404. At the trial preparation conference, plaintiff stated that he intends to impeach Dr. Pitzer with evidence that he lied about a driving while ability impaired conviction at depositions in other cases and in connection with the renewal of his medical license. Plaintiff claims that such evidence is relevant to Dr. Pitzer’s credibility.

Federal Rule of Evidence 608(b) bars extrinsic evidence to “prove specific instances of a witness’s conduct in order to attack or support the witness’s character for truthfulness.” A court may, however, allow an attorney to inquire into such instances on cross-examination so long as the specific conduct is “probative of the character for truthfulness or untruthfulness” of the witness. Fed. R. Evid. 608(b)(1). Admissibility of intrinsic evidence of specific conduct is subject to the court’s discretion under Rule 403. See United States v. Torres, 569 F.3d 1277, 1283 (10th Cir. 2009) (decision to admit evidence under Rule 608(b) is at the discretion of the district court); United States v. Girdner, 773 F.2d 257, 261 (10th Cir. 1985) (“The court did not abuse its discretion in allowing cross-examination of appellant’s previous falsehoods and deceitful actions in the ballot fraud scheme as being probative of appellant’s truthfulness.”).

Under Rule 608(b), plaintiff may not introduce extrinsic evidence of Dr. Pitzer’s offense or his subsequent statements about it. See Fed. R. Evid. 608(b). But neither Rule 403 nor Rule 608(b) bars plaintiff from cross-examining Dr. Pitzer about whether he has previously concealed or made false statements about the offense. See Torres, 569 F.3d at 1282-83.