Gunman in Oregon College massacre committed suicide: authorities

26-year-old Christopher Harper-Mercer, the gunman responsible for the Oregon Community College killings {PHOTO: COURTESY}

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.

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 on Saturday 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 on Thursday and shot the professor at point-blank range, before picking off other victims one at a time as he questioned each about their religion and whether they were Christians.

In a brief statement issued on their behalf by state police on Saturday, the gunman's family said they were "shocked and deeply saddened by the horrific events," and said their thoughts and prayers go to the relatives of the dead and injured.

Late on Friday, it emerged that Harper-Mercer 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.