If a pattern of behavior is not invariable or almost invariable, it is not habit.

Fed. R. Evid. 9019(b)(1) ("Testimony that a matter is what it is claimed to be.").A matter may be authenticated by the testimony of a witness who has personal knowledge that the matter is what its proponent claims it is.

United States v. Goings, 313 F.3d 423, 426-427 (8th Cir. 2002) (conviction for theft and conspiracy to commit theft from an Indian tribal organization; accused argued that the district court erroneously excluded certain evidence about other employee loans and loan procedures; court affirmed conviction...During the cross-examination of a witness -- and during any examination of a witness who is a permissible target for impeachment -- the witness may be asked about specific acts that are indicative of the witness's untruthfulness if such acts are relevant to and probative of the witness' truthfulness or untruthfulness, unless the trial court determines that the acts inquired into are unduly prejudicial.

United States v. Koen, 982 F.2d 1101, 1110 (7th Cir. 1992) (upholding trial court's admission of witnesses' testimony about accused's business dealings because, even though the accused does not dispute that this evidence establishes his indebtedness and his motive, still such evidence completed the...Another act, wrong, or crime is admissible to show a motive for some alleged conduct on a particular occasion.