The gunman who killed his English professor and eight others at an Oregon community college committed suicide after a shootout with police who were on the scene within five minutes and exchanged fire with him almost immediately, authorities said Saturday.
Investigators had previously said the 26-year-old shooter was killed by the officers who raced to the rampage at Umpqua Community College in Roseburg, which ranks as the deadliest among dozens of U.S. mass shootings in the past two years.
Douglas County Sheriff John Hanlin told a news conference that the state medical examiner had determined that the gunman, Christopher Harper-Mercer, took his own life.
Releasing a timeline of the first hour of the massacre, Hanlin said two Roseburg police officers were on the scene within five minutes, and reported to dispatch that they had engaged the gunman just two minutes later. Hanlin said they "neutralized" him.
"Officers responded immediately ... there was an exchange of gunfire, (and) the shooter was neutralized at that point in time," the sheriff said. "As far as the very specific information regarding whether it was an officer's bullet or his own bullet, we aren't prepared at this time to discuss."
Hanlin said an additional handgun was also recovered from the shooter's apartment, making a total of 14 weapons seized: eight from his home, and six he took to the college.
Harper-Mercer was officially identified on Friday as the assailant who survivors said stormed into the classroom of his introductory writing class to shoot the professor at point-blank range, then began picking off other victims one at a time as he questioned each about their religion and whether they were Christians.
Late on Friday, it emerged that he was once turned away from a firearms academy by an instructor who recalled finding him "weird" and "a little bit too anxious" for high-level weapons training.
Harper-Mercer had a month-long stint in the Army in 2008 and a preoccupation with weaponry that dated back at least two years.
He sought to register for training in 2012 or 2013 at Seven 4 Para, a private self-defense and law enforcement training academy in Torrance, Calif., but Eloy Way, president and head instructor for the center, said he sent Harper-Mercer away.
"We wanted him to take a beginner safety course and he was trying to tell me that he already had experience with firearms and I didn't get a good feeling about him, so I turned him down," Way told Reuters.
"He was just kind of a weird guy and seemed kind of spoiled, immature," Way said. "He was a little bit too anxious to get high-level training and there was no reason for it."
Authorities have disclosed little of what they may know about the gunman's motives.