Testimony by witnesses that San Diego Police Agent Donovan Jacobs beat 25-year-old Sagon Penn with his fists and night stick and that he berated Penn with racial epithets is being reviewed by the state attorney general's office as it looks into alleged officer misconduct in connection with Penn's murder trial, sources close to the probe said. Penn was tried and acquitted twice in the March, 1985, killing of Police Agent Thomas Riggs and the wounding of a ride-along civilian. Jurors said they believed defense contentions that Penn was attacked by Jacobs and reacted in self-defense. At the same time, Jacobs' conduct was criticized for the first time by a member of the slain officer's family. Michael Riggs, a younger brother, said that he believes Jacobs is a bigot whose actions caused Penn to fire the fatal shot.