Satterberg called a late morning news conference to announce charges against the suspect, 26-year-old Aaron Ybarra of Mountlake Terrace, who had spent weeks planning the attack, according to court documents.
The prosecutor said multiple felony charges are being filed against Ybarra, including a charge of first-degree murder for the death of Paul Lee of Portland, Ore. Ybarra also will be charged with two counts of first-degree attempted murder and one count of second-degree assault.
On Tuesday afternoon, shooting victim Sarah Williams released a statement thanking everyone for their support and asking for privacy as she heals.
"I know there is a lot of concern for my health and well being, so I'd like to take this opportunity to let everybody know that I am healing and getting stronger. The doctors and hospital staff at Harborview Medical Center have been fantastic and they are taking excellent care of my family and me.
William remains in Harborview Medical Center in satisfactory condition. There is no immediate timeline for when she'll be released from the hospital.
"While every day brings improvement, I have a long way to go for full recovery. During that time, I truly do wish that everyone please respect my privacy and that of my family. We are interested in only one thing: being together and getting through this," Williams said in her statement.
Satterberg said the standard sentencing range for those crimes, if Ybarra is convicted, would result in a prison term of 69 to 86 years. But Satterberg said he will seek a life sentence due to aggravating circumstances.
Court papers obtained by KOMO News say Ybarra arrived at the SPU campus at about 3:25 p.m. Thursday armed with a shotgun and a hunting knife.
Ybarra first shot Paul Lee in the back of head outside Otto Miller Hall, according to the case file. Those documents say Ybarra chose Lee because he thought Lee did not take him seriously enough when he pointed the shotgun at him.
Stray pellets from that first shotgun blast also struck another student, Thomas Fowler, who was standing about 7 or 8 feet away and ran from the scene after being hit.
Ybarra then tried to shoot a female student standing nearby but she managed to run away when the second shotgun barrel malfunctioned. He ejected the misfired round, then entered Otto Miller Hall, according to court records.
Once inside he pointed his shotgun at another student who was studying at a table but did not shoot him. Instead, he shot another student, Sarah Williams, as she was coming down the stairs after a math test, charging documents say. He later told police he shot her because he felt she did not show him the proper "respect," according to the case file.
The student at the table then began to run and Ybarra tried to shoot him, but again the shotgun misfired.
As he went to reload the weapon again, Ybarra was pepper-sprayed in the face and wrestled to the floor by student security monitor John Meis, who saw what was happening and took quick action.
Meis managed to disarm Ybarra and quickly lock his shotgun in a nearby office before coming back and taking away Ybarra's hunting knife, court documents say.
Then, with the help of two other students, Meis held Ybarra for police officers responding to the shooting.
Police say Ybarra had about 50 additional shotgun rounds and told investigators he planned to shoot as many people as possible and then kill himself with the hunting knife if officers did not shoot him first.
"Jon Meis is an authentic hero," Satterberg said Tuesday. "Mr. Meis, though a reluctant and humble figure in this tragedy, undoubtedly saved many lives."
Ybarra is being held without bail and has been on suicide watch at King County Jail. His lawyer says he has a long history of mental problems.
Satterberg said Ybarra had kept a journal that "clearly established his intent to commit an act of mass violence," and that he decided on Seattle Pacific University shortly before the attack after also considering Central Washington University and Washington State University.
Ybarra scouted out the campus before the attack, and was even shown around by helpful students and a staff member who did not know his intentions. He said he checked for possible escape routes students might use in attempting to flee the building and chose birdshot ammunition because he thought it would spread wider and cause more damage than buckshot, court papers say.
In his journal Ybarra also expressed an admiration of perpetrators of other acts of mass violence. He did not know any of the victims he shot and was not targeting anyone specifically.
"He stated that he just had a hatred for the world in general," charging documents say.
On the day of the attack, Satterberg said the suspect wrote: "I just want people to die and I'm going to die with them."
Ybarra told police that he had been diagnosed with mental problems but that he had stopped taking his medications and quit going to therapy about six months ago because "he wanted to feel his hate," Ybarra told investigators.