A homeless man who admitted killing Iowa State University golf star Celia Barquin Arozamena has apologized for his savage act, saying he’s sorry for “stripping a life from society.”

The handwritten note to a judge by Collin Richards, 22, was filed Tuesday in Story County, where he’s set to be sentenced on Aug. 23 to life in prison without parole for stabbing Barquin Arozamena, 22, several times as she took a morning run at Coldwater Golf Links in Ames, the Des Moines Register reports.

“I want you to know [how] sincere I am,” Richards wrote. “I want to show remorse for stripping a life from society … worse from a loving family. I want the family and you to know I’m sorry.”

Richards, who pleaded guilty to first-degree murder in June, said he now intends to refocus his life to change for the better.

“I will use all resources and steps,” the note continued. “If there is anything I can do, I will. Thank you for the time and for working with me.”

Cops have recovered three knives in connection with the golf star’s killing, including two kitchen knives longer than 4 inches — one of them serrated — that were found in a garage fire at a home where Richards allegedly showered three days after the September 2017 slaying.

The body of Barquin Arozamena — a native of Spain and Iowa State’s female athlete of the year in 2018 — was found stabbed multiple times with injuries to her upper torso, head, neck and left leg, leaving blood on the golf course’s fairway, the Des Moines Register reported.

Richards had scratches on his face and arms when he was stopped by police shortly after the gruesome murder and told an acquaintance days earlier that he had urges to “rape and kill a woman,” authorities said.

Barquin Arozamena, a civil engineering major who became the Big 12 women’s golf champ in 2018, was apparently missing some clothing when she was found dead on the course wearing a sports bra and golf shirt, investigators have said.