(CNN) -- The man accused of opening fire at a Seattle college had a fascination with school shootings, telling investigators he had once visited Columbine High School, a police source told CNN affiliate KIROon Friday.
According to the unnamed police source, the suspect admitted to the attack and told police he "wanted to shoot up a school."
Aaron Ybarra, 26, of Mountlake Terrace, was ordered held without bail in connection with the shooting at Seattle Pacific University that left one dead and two wounded, Leesa Manion, a spokeswoman for the King County prosecutor, said. Charges against Ybarra are pending, she said.
The shooting at the university on Thursday afternoon began when a man armed with a shotgun opened fire inside Otto Harris Hall, which houses the engineering, math and science departments.
Authorities say the gunman walked into the building's foyer, confronted three students and then shot them.
The shooting rampage ended when a student security guard doused the shooter with pepper spray and tackled him as he tried to reload his shotgun, police said.
Ybarra isn't a student at the school. Police say they think he acted alone, but the investigation is continuing.
"So far, police have not found any connection between the suspect, Seattle Pacific University or any of the victims," according to statement released by the Seattle Police Department.
Ybarra had a history of mental health problems and is on suicide watch at the jail, public defender Ramona Brandes said
Ybarra has "significant and long-standing mental health issues, including delusions that were in play" at the time of the shooting, she told reporters.
"...He's on suicide watch for a reason. He did not think he was going to survive yesterday. He intended to die."
She declined to comment on what Ybarra told authorities, including his claim that he visited Columbine -- the Colorado school where a mass shooting carried out by two students in April 1999 left 13 people dead and 24 wounded.
Brandes said Ybarra is aware of what happened.
"He is cognizant of the suffering of the victims and their families and the entire Seattle Pacific community," she said. "He is sorry."
Ybarra had several run-ins with police in recent years. He was taken into custody in 2010 and 2012 for a mental health hold, Mountlake Terrace Assistant Police Chief Pete Caw told CNN. In both cases, authorities determined Ybarra was intoxicated, incoherent and suicidal, Caw said.
The image of the suspect as a gun-toting killer is a difficult one to reconcile for those who know him.
One friend described Ybarra as "socially awkward" but "appreciative," according to CNN affiliate KOMO.
"I have no idea what set him off," said Nate Flesch. "That's why this whole thing kind of surprises me -- that he was trying to turn his life around, that he was trying to be a better person, and he was kind of working on his social skills, too."
Ybarra is accused of killing Paul Lee, a 19-year-old student, authorities said.
One of the wounded, a 19-year-old woman, remained unconscious and in critical but stable condition Friday after five hours of surgery the day before, Susan Gregg of Harborview Medical Center said.
A second patient, a 24-year-old man, was in satisfactory condition and could be released as early as Saturday, she said.
Police are convinced the shooter would have killed or wounded more people had those around him not intervened.
"This story is not about an evil act but about the people that actually lived through this scenario and assisted each other when things were pretty tragic," said Seattle police Assistant Chief Paul McDonagh.
University President Daniel J. Martin praised the school's students, emotionally telling CNN affiliate KCPQ that they had "acted without regard for their own safety."
KOMO identified the student security guard who tackled the suspect as Jon Meis.
"He saw the guy and got his pepper spray, sprayed him and tackled him," Meis' friend Patrick Maguire told KOMO.
Maguire said he's not surprised that Meis didn't hesitate to put his own life in danger to save others.
"I could have been one of these people that was injured or in critical condition," he said. "A lot of (students) were in that building and he stopped him in the lobby. He didn't get any farther than that. I'm grateful for him.