A gunman with a history of threatening medical workers was arrested for opening fire at a Buffalo, Minn., health clinic on Tuesday, killing one person and wounding four others in what authorities called "a horrible-looking scene."

Gregory Paul Ulrich, 67, was jailed after the shootings that stunned and locked down parts of the community 40 miles northwest of the Twin Cities just before 11 a.m.

Authorities did not release the name of the victim who died at HCMC in Minneapolis after being taken by ambulance from the scene at Allina Clinic on Crossroads Campus Drive; three other people remained in critical but stable condition at North Memorial Health Hospital on Tuesday evening and a fourth had been released.

A man who roomed with Ulrich as recently as July told the Star Tribune that Ulrich had binged on painkillers and was irate at a doctor who would not prescribe more.

Buffalo Police Chief Pat Budke was overcome with emotion and struggled to speak at times as he briefed the news media on the day's tragedy.

"Our heart breaks as a community. This is a day that no community would want to go through," he said.

Ulrich, a longtime resident of Buffalo, had "multiple contacts" with law enforcement dating back to 2003, Budke said, and had a history of being unhappy with health care he had received.

Police reports show Ulrich had made threats of a mass shooting at the clinic in October 2018, with a doctor telling authorities that Ulrich had talked about "shooting, blowing things up, and practicing different scenarios of how to get revenge."

Ulrich told authorities then that he had just been telling the doctor about his dreams and wouldn't actually do anything, the report said. He mentioned having medication issues after back surgeries.

Citing his history, authorities said they were confident Ulrich acted alone. "The history we have with this individual makes it most likely that this incident was targeted at that facility or someone in that facility," Budke said. "Because of that previous contact with him, this was an isolated incident or only directed at people within [the clinic]."

Authorities called bomb experts to the area after finding a "suspicious package" at the hospital and "suspicious devices" at a Super 8 motel, where Ulrich had reportedly been staying.

It was unclear whether any explosives had been detonated. Budke said "there may have been [an explosion] before" the shooting.

Send ambulances

The initial dispatch reports indicated that multiple people called 911 about an "older white male" in the clinic with a handgun.

One dispatcher said his partner was on the phone with the suspect doing the shooting. "He is saying that there are bombs inside," the dispatcher is heard saying. "He is telling law enforcement to back off."

The man let a woman out of the clinic, but authorities were "not sure about other hostages," the audio continued.

The suspect was in the front vestibule while "saying that he does want to surrender now. … The male is going to stay in place, he is laying on his stomach. … The male is saying the gun is inside the building somewhere."

Sheriff Sean Deringer said that once Ulrich was arrested and the threat was over, responding officers rushed to help the wounded. "It was a horrible-looking scene," Deringer said.

The dispatch audio illustrated a frantic scene as victims streamed outside the hospital and officers rushed to evacuate them.

"I've got four or five with gunshots back here," an officer said, adding that at least three of the victims were women, with one shot in the abdomen and another in the spinal cord, according to the audio. "Send as many ambulances as you can."

Neighbors avoided him

As news of the shooting and arrest spread in the Central Minnesota community, Ulrich's longtime neighbors at Pulaski Mobile Home Park were grappling with revelations that a man they all knew — and many tried to avoid — might be responsible.

Ulrich's former roommate, Raymond Zandstra, said he was not surprised when he heard law enforcement on television reveal who they had arrested as a suspect. Zandstra, who now lives in Maple Lake, said he rented a room from Ulrich for about 18 months until July.

He said Ulrich would take "a month's worth of painkiller, and he'd have that gone in a week and a half. He'd get a buzz on them."

Zandstra said Ulrich was so irate that he put the physician's name on a sign calling the doctor "a crook and just no good," and attached it to the mobile home's shed "facing the main road going to the hospital so everybody could see it."

Neighbor Bob Taylor said Ulrich was not well-liked in the trailer park where everyone knew everyone.

"He was creepy, give you dirty looks," Taylor said. "He had a blank stare all the time."

But neighbor Walter Rohde had a different take on Ulrich.

Rohde said Ulrich helped him build a shed over the summer and would often come over to sit at his fire ring in the evenings to chat.

Rohde said Ulrich was unemployed, living on disability and carried a heavy backpack around town with him, walking because he didn't have a car.

Ulrich has lived in the mobile home park for several years but recently put his trailer up for sale, Rohde said.

Residents reeling

In the hours after the shootings Tuesday, stunned Buffalo leaders and residents struggled to come to grips with the tragedy.

Mayor Teri Lachermeier urged people to support the victims and others affected by it.

"I want to say, we're going to make it through this. It's going to be difficult. This doesn't happen in Buffalo, Minn. Right?" Lachermeier said. "But we need to be there for these people that are needing us. We've got to reach out in this time of COVID when you can't physically hug someone, we need to reach out by phone and make sure everyone is OK."

Jen Sherwood had been putting groceries in her SUV in the parking lot at Cub, a short distance from the motel where police had blocked off the streets. She had two children in the vehicle.

She said she had been following news developments on her cellphone.

"It's scary," she said. "I know they caught the guy but they still have the streets blocked near the Super 8. It's unnerving. You wonder what's going on."

Steve Markve, 53, of Buffalo said he was not surprised that the shooting had occurred. "After several decades of [major] gun violence in America, you wondered when it's coming to the neighborhood," he said.

Cub Foods employee Steve Gertsema of Monticello said simply, "it's too close to home."

Ulrich is expected to appear in court Thursday morning.

Staff writers Andy Mannix, Matt McKinney, Libor Jany and Randy Furst contributed to this report.