Forty years ago, Mr. Flick was living in Westbrook, Me., working at a doughnut shop and facing the end of his marriage. His wife, Sandra Flick, served him with divorce papers and had police officers remove him from their apartment. But, when he came to get his belongings, he was armed with a jackknife.

Ms. Flick’s daughter from an earlier marriage, Elsie, hid in a bedroom and watched as Mr. Flick bent her mother’s arm behind her back and covered her mouth with his hand. The daughter fled the apartment. When a neighbor went up to check on Ms. Flick, he saw Mr. Flick on the stairs, covered in blood, and found Ms. Flick stabbed four times in the neck and chest, and once through her heart.

Mr. Flick was convicted in his wife’s murder and spent 25 years in prison. But the violence continued after his release: He was convicted of punching and stabbing a woman — who a prosecutor said was a girlfriend — with a fork in 2007, and of assaulting and threatening another woman with whom, a prosecutor said, he had a sexual relationship, in 2010.

A prosecutor then urged a judge to sentence Mr. Flick to about eight years in prison, calling him a danger to society and women. Despite his age — then in his late 60s — she told the judge that he was not about to stop.

Judge Robert E. Crowley cut that recommendation in half, sending Mr. Flick back to prison for less than four years.