SEATTLE -- The man blasting away with a shotgun paused to reload, and Jon Meis saw his chance.
The 22-year-old building monitor pepper-sprayed and tackled the gunman Thursday in Seattle Pacific University's Otto Miller Hall, likely preventing further carnage, according to police and university officials.
Mr. Meis and other students subdued the gunman until officers arrived and handcuffed him moments later.
Police said the shooter, who killed a 19-year-old man and wounded two other young people, had 50 additional shotgun shells and a hunting knife. He told authorities after his arrest that he wanted to kill as many people as possible before taking his own life, Seattle police wrote in a statement filed in court Friday.
Friends credited Mr. Meis with saving lives. "I'm proud of the selfless actions that my roommate, Jon Meis, showed today taking down the shooter," fellow student Matt Garcia wrote on Twitter. "He is a hero."
The suspect, Aaron R. Ybarra, 26, has a history of mental health problems for which he had been treated and medicated, said his attorney, public defender Ramona Brandes. He is on suicide watch at the jail. "He is cognizant of the suffering of the victims and their families and the entire Seattle Pacific community," Ms. Brandes said. "He is sorry."
Mr. Meis, a dean's list electrical engineering student, was emotionally anguished but not injured in the shooting, Susan Gregg, Harborview Medical Center spokeswoman, said Friday. He was treated and released.
Mr. Meis, who graduated from Seattle Christian Schools in SeaTac, kept a low profile the day after the shooting. A voice message on a phone listing for his parents' home in Renton said: "We ask that you please respect our privacy during this time while we recover." It solicited prayers for students and the family of the man killed.
Roman Kukhotskiy, 22, was in the building when the violence broke out. He said Mr. Meis is getting married this summer and has accepted a job with Boeing, where he has interned in previous years. "I was amazed that he was willing to risk all that for us," Mr. Kukhotskiy said. "If Jon didn't stop him, what's to say? I could have been the next victim."
Salomon Meza Tapia, a friend who serves with Mr. Meis on the board of a student engineers group, described him as a hardworking student who is "always super chill." In an email, Mr. Tapia said: "I am not surprised he was cool and collected enough to take action. I was in the building, and I can say he definitely saved our lives. I am thankful to be alive, and thank God for Jon Meis' courage and actions."
Seattle Mayor Ed Murray identified the student killed as Paul Lee, a "Korean-American student with a bright future."
The gunman had just entered Otto Miller Hall when he opened fire in the foyer. Classes were taking place upstairs. Wounded in the shooting were a 19-year-old woman who remained in intensive care Friday after a five-hour surgery, and a 24-year-old man in satisfactory condition, the medical center's Ms. Gregg said. Their identities were not released.
The leafy campus of the private, Christian university about 10 minutes north of downtown Seattle was quiet the morning after the shooting, with a service held at midday. People stopped to pay their respects at a makeshift memorial near the science and engineering building where the shooting occurred.
On Friday, Mr. Ybarra wore a protective vest at his appearance in a jailhouse courtroom. A judge found probable cause to keep him detained without bail at the King County Jail.
Mr. Ybarra was hospitalized for mental health evaluations twice in recent years, said Assistant Police Chief Pete Caw of Mountlake Terrace, a northern Seattle suburb and Mr. Ybarra's hometown.
In 2010, officers responded after Mr. Ybarra, heavily intoxicated, called 911 to report that he "had a rage inside him" and wanted to hurt himself and others, according to a report Mountlake Terrace police released. In 2012, police found him lying in a roadway, again severely intoxicated. He told officers that he wanted a SWAT team "to get him and make him famous," a police report said.
Both times, police took Mr. Ybarra to Swedish Hospital in Edmonds for evaluation, Assistant Chief Caw said.
Mr. Ybarra is not a Seattle Pacific student, police said. His friend, Zack McKinley, described him as "super happy and friendly," The Seattle Times reported. Mr. McKinley said the attack was puzzling because Mr. Ybarra was happy to have just started a job bagging groceries. He could get emotionally low but had a good group of friends, Mr. McKinley said.