RENO, Nev. -- Newly released 911 tapes paint a scene of panic and terror inside a Reno medical building where dozens of callers hid in bathrooms and exam rooms from a suicidal gunman who killed one doctor and shot another at a urology clinic where he said he'd had a vasectomy that ruined his life.
Callers included a woman hiding under a desk in an exam room and another who whispered "Oh, my God" and "he's going to ... kill us" as apparent gunshots can be heard in the background on the tapes released Tuesday.
Alan Oliver Frazier, 51, told patients to leave or he'd shoot them after he entered the Urology Nevada office last week and soon began firing a pistol-grip, 12-gauge shotgun.
The shooter from Northern California said he was angry because "he had a vasectomy here and they ruined his life," a male witness told a dispatcher from a locked bathroom where he and about 10 others hid.
"He says, `As long as you're a patient, you can leave. Otherwise I'm going to shoot you,"' the man said. The bathroom was just outside the urology office where the shooting occurred.
A woman hiding under a desk was talking so softly she could barely be heard.
"I hear gunshots outside my office," the woman said. "I just heard another one. ... He's going to (expletive) kill us."
"Oh, my God. ... He's outside my door," she said.
Among the 50 calls police said they received just after 2 p.m. on Dec. 17 while Frazier still was considered an active shooter was a woman in a locked office, gasping for breath between sentences.
"He's in the middle of the office," she said. "We think he shot one of our doctors."
Police began arriving at the scene within minutes, and entered Urology Nevada while some callers still were on the phone.
Police confirmed Tuesday Frazier had been a patient at the facility, and complained about a botched surgery in 2010.
The unemployed former power plant worker made it clear in a suicide note that he planned the attack and that his focus was on the physicians at Urology Nevada, police said. Authorities have not said who operated on Frazier, who lived near Lake Almanor, about 130 miles north of Reno.
Detectives are "actively looking into" Frazier's involvement in an Internet chat room where he reportedly complained about complications from the surgery, city spokeswoman Sharon Spangler said.
She confirmed investigators are interviewing a former fiancee of Frazier's who told The Associated Press he took medication for depression when they were together in the mid-1990s. They're also talking to a neighbor who said Frazier told him the day of the shooting that he was leaving and not coming back.
Police haven't determined if Frazier had a history of mental illness. But Spangler said detectives are in contact with the ex-fiancee, who told the AP he was a different person when he didn't take his medication for depression and was suicidal at least once during the 18 months they were together.
Spangler also acknowledged investigators talked to the neighbor, Mike Hawthorne, who told the Reno Gazette-Journal that Frazier said the day of the shooting he wouldn't be back.
Citing a neighbor, the Gazette-Journal first reported that Frazier sometimes ranted in a Yahoo group about vasectomy pain that he was still suffering more than two years after what he claimed was a botched surgery.
Witnesses told investigators that Frazier said during the attack that he was looking for physicians. He used the shotgun to kill Dr. Charles G. Gholdoian, 46, president of Urology Nevada. He also critically wounded Dr. Christine Lajeunesse and seriously injured Shantae Spears, who was accompanying a relative on an office visit. Frazier then turned the gun on himself.