Plea negotiations and discussions

Fed. R. Evid. 608(a) ("The credibility of a witness may be ... supported by evidence in the form of opinion or reputation, but subject to these limitations: (1) the evidence may refer only to character for truthfulness or untruthfulness, and (2) evidence of truthful character is admissible only after the character of the witness for...If one party uses reputation or opinion evidence to impeach a witness, an opposing party may use, respectively, either reputation evidence or opinion evidence about truthfulness to rehabilitate the witness.

Koloda v. General Motors Parts Div., 716 F.2d 373, 376 (6th Cir. 1983).To be admissible, prior events or accidents must be substantially similar to those at issue in trial.

United States v. Matlock, 109 F.3d 1313, 1319 (8th Cir. 1997) (two defendants pled guilty and one was convicted of drug-related offenses following a jury trial; defendant Lipscomb argues that co-defendant Matlock's plea hearing testimony does not fall within Rule 801(d)(1)(A) because the plea hearing...A prior inconsistent statement is exempt from the federal hearsay rule pursuant to Federal Rule of Evidence 801(d)(1)(A) or by a comparable State rule only if the prior statement is in fact inconsistent with the declarant's testimony at the trial or with some other statement of the declarant that is admitted into evidence pursuant to some hearsay exemption or exception.