PORTLAND, Ore. (KOIN) — After reviewing the Umpqua Community College shooting, no criminal charges will be filed against anyone, authorities said Friday.

The Douglas County Sheriff’s Office said they completed their investigation regarding the October 2015 shooting in Roseburg and that the Douglas County District Attorney’s Office also reviewed the facts surrounding the incident.

Authorities determined the shooter–26-year-old Christopher Harper-Mercer — acted alone and died of a self-inflicted gunshot wound to the head after exchanging gunfire with officers.

The shooter killed 9 people and injured others before shooting himself on the college campus. Witnesses said he asked students what their religion was before spraying more bullets.

Nearly 3,000 students were on campus at the time of the shooting.

In a joint statement Friday morning, Sheriff John Hanlin and District Attorney Rick Wesenberg said,

Our offices wish to extend our deepest condolences to all those affected by this horrific and cowardice act of violence. We wish to express our thanks to the countless number of community members from Douglas County and across the world who offered their support during this investigation. Additionally, we wish to thank our public safety partners from Oregon and all over the United States for their response to the college campus.”

Oregon authorities release ‘manifesto’ from mass shooting

PORTLAND, Ore. (AP) — Oregon authorities have released a detailed report on a mass shooting at a community college that includes a six-page, typewritten “manifesto” that says the shooter had studied the methods of other mass killers.

The report was released Friday involving the attack by 26-year-old Christopher Harper-Mercer that left nine people dead and nine others injured in 2015 at Umpqua Community College in Roseburg, Oregon.

In the document left on a thumb drive for police to find, Harper-Mercer says he serves the “demonic Hierarchy” and will become a demon when he dies and return “to kill again and again.”

He also makes it clear that he idolizes other mass shooters and says he has studied their methods to figure out how to kill more people. Harper-Mercer committed suicide after he was injured by police during the Oct. 1, 2015, shooting.

Authorities found nine guns stashed in his backpack, in a college restroom and at his home.