RENO, Nev. — Authorities on Friday were trying to determine whether a northern California man’s anger over complications he suffered from a 2010 surgery prompted him to go on a shooting rampage at a Nevada urologist’s office, killing one doctor and critically wounding another before committing suicide.

Reno Police Lt. William Rulla said detectives were working to obtain Alan Oliver Frazier’s medical records to learn more about his physical and mental health.

Frazier, 51, made it clear in a suicide note that he had planned the attack and that his “focus was on the physicians at the specific office,” Rulla said. Police recovered the note at Frazier’s home.

Investigators have declined to specify the kind of surgery he had or say whether the doctors he targeted had anything to do with it.

But a couple who lived across the street from Frazier at Lake Almanor, about 130 miles north of Reno, said the operation he had was a vasectomy. They also said Frazier frequently posted complaints in an online chat group about the pain he suffered from what he claimed was a botched surgery.

An expert in men’s reproductive health care said that while it’s uncommon, some men experience pain more than two years after a vasectomy.

Neighbor Mario Tognotti told The Associated Press on Friday that Frazier told him and his wife that he sought help from doctors for his pain and had approached a lawyer about the situation.