D is charged with child sex offenses. P offered evidence of sex offenses committed by D against a niece of his first wife during that marriage, between 1985 and 1987. This niece, T.T., would testify that D had played games with her at her aunt's house, had exposed himself to her, had forced her to touch his penis, and had touched her private parts just the same as 'C.D.' did in the present case. In D's first trial, the government offered the evidence under Rule 404(b). It was not then able to offer the evidence under Rule 414 because of its failure to provide timely notice of the offer, as required by Rule 414. The District Court admitted the evidence, and the jury convicted D. On appeal, the Court held that the admission of the evidence under Rule 404(b) was improper, and reversed D's conviction. On remand, D moved in limine to exclude the evidence. The District Court ruled that T.T.'s testimony was potentially admissible under Rule 414, but excluded by Rule 403. P appealed.