(CNN)The 67-year-old man accused of killing one person and wounding four others at a health care clinic in the Minnesota city of Buffalo was "very familiar" to law enforcement and was upset with his treatment, authorities said Tuesday.
One dead and four wounded in shooting at Minnesota health care clinic
Gregory Ulrich was taken into custody after the morning shooting at the Allina Health Care Clinic. Buffalo Police Chief Pat Budke said that most likely the shooting was "targeted at that facility or someone within that facility" given the suspect's history of conflict.
"We are very familiar with the suspect," he said. "There is a history of him being unhappy with health care -- with the health care he received," he said, adding the suspect has lived in the area a "long time."
Authorities said they believe Ulrich acted alone. Budke said he didn't know how many shots had been fired.
One person died at a hospital and three others, who were taken to another facility, were in critical but stable condition, according to hospital officials. One victim was treated and released from North Memorial Health Hospital, according to a news release obtained by CNN affiliate KARE.
Police received a 911 call about shots fired just before 11 a.m., Budke said. When officers arrived they found multiple victims and took the suspect into custody.
Officers found a suspicious package in the corner of the health clinic's lobby, according to Wright County Sheriff Sean Deringer. Police also found several suspicious devices at a nearby Super 8 motel where the suspect was staying, Deringer said.
The sheriff described the clinic as "a horrible looking scene" when he arrived, and after emergency responders rendered aid and removed the victims, the suspicious package was found during a secondary search.
"We have contacted the Minneapolis Bomb Squad, and they are on scene right now helping us with that," Deringer told reporters. Agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives were assisting, officials said.
The police chief didn't comment on reports of explosions heard at the clinic or what investigators found.
"We don't know or can't confirm what those devices were or really anything about what the intention behind those devices might have been until we're able to complete the investigation," Budke told reporters at a news conference.
The suspect will appear in court Thursday at 10:30 a.m., Wright County Attorney Brian Lutes said. It is unclear whether he has an attorney.
Deringer said Ulrich's history with law enforcement dates to 2003.
The clinic's website describes the location as a convenient health care option and part of the Buffalo Crossroads family clinic.
"Our hearts were broken Tuesday ... We are a family at Allina Health and this was an incredibly traumatic day for our entire organization, the patients we serve and the community of Buffalo," the company noted in a statement.
Buffalo is about 40 miles northwest of Minneapolis. The city has a population of about 16,000 people, and the city's residents are about 97.5% White with a median household income slightly above the state average, according to the US Census.