U.S. v. Beechum, 582 F.2d 898 (5th Cir. 1978) involved extrinsic offense evidence but not by a third party. In Beechum, the court set out the two-step test to determine whether extrinsic offense or bad act evidence would be admissible. First, the extrinsic evidence must be relevant to an issue other than the defendant's character. Id. at 911. Second, the evidence must have probative value that is not substantially outweighed by undue prejudice and meet the other requirements of Rule 403 of the Federal Rules of Evidence. Id. The court went on to state that it was obvious that if the defendant did not commit the extrinsic act or offense, the evidence was irrelevant and inadmissible. Beechum, 582 F.2d at 912-913. The government was required to offer proof demonstrating that the defendant committed the act. Id. at 913.