In August 2015, Ken Starr, then president of Baylor University, issued a bold pronouncement to students and faculty. “By God’s grace,” he wrote, “we are living in a golden era at Baylor.”

Less than a year later, the university’s regents voted to remove Mr. Starr after six years on the job, saying he failed to act as charges of sexual assault upended the football team and swept the nation’s largest Baptist university, a place where biblical verse is carved into the sidewalks.

Mr. Starr, 73, has held many high-profile national posts, including solicitor general and independent counsel. Now he will work on the legal team defending President Trump in his impeachment trial. But his tenure as president of Baylor and its 14,000 students registers as a dark chapter in his career. Young women and several former officials said in interviews that Mr. Starr ignored the women’s cries for help and that he and other top officials at Baylor failed in their responsibility to shield the women from sexual harm.

Three years ago, 15 current and former female students filed a lawsuit against Baylor, saying they had been raped or assaulted by fellow students, one of whom was a football player. Their case has unearthed piles of unsightly evidence of official inaction.