Dr. Donald Dutton was called by the prosecution in January 1995 and accepted by stipulation, for purposes of the hearing, as an expert on the dynamics of spousal assault. He testified about battered women's syndrome and described his research as psychological profiling of men referred for treatment for wife assault, comparing their profiles with wives' reports of physical, emotional, and other abuse. In the pretrial admissibility dispute, his testimony addressed controlling behavior, estrangement, and intimate-partner homicide risk; F. Lee Bailey cross-examined him about whether he could ethically opine on Simpson and whether the hypotheticals fit batterer patterns, followed by redirect and recross.