More than a third of the offenders and about half of the mothers had experienced or been exposed to sexual abuse as children. Cases were divided into those where the sexual abuser was the biological father in an intact family, those where he was a stepfather or mother's live-in partner, and those where he was a noncustodial father. In biological father cases, parents were about equally likely to have experienced sexual abuse during childhood. The mother was more likely to have had such an experience in the stepfather/live-in partner cases. And, the offender was more likely to have come from a sexually abusive family in the noncustodial father cases. 3 tables, 29 references. (Author abstract modified)