SAN FRANCISCO—At a panel discussion Monday night, U.S. District Chief Judge Phyllis Hamilton of the Northern District of California shared a recollection about a prosecutor who was known around the courthouse as “very stylish.”

Hamilton said she and her law clerks noticed that, when the prosecutor had a trial, she wore the same two suits on alternating days. Hamilton said initially she didn’t think anything of it. But when jurors returned questionnaires after the case was over, Hamilton said that at least half of them asked why the prosecutors kept wearing the same two outfits.