Testimony of a former Portland police officer resumed Monday in the ongoing post-conviction review hearings for Anthony J. Sanborn Jr., the 45-year-old convicted murderer who is attempting to clear his name after nearly 30 years in prison. Daniel Young, one of the detectives who investigated the murder of Jessica L. Briggs, 16, returned to the witness stand to parse through his hand-written notes made during interviews following the May 1989 slaying. Sanborn’s attorney, Amy Fairfield, is comparing Young’s notes from the investigation taken by hand with the typed reports that were submitted as discovery to Sanborn’s original defense team. The testimony is painstaking.