Christopher Harper-Mercer, the gunman in Thursday's mass shooting at Umpqua Community College in Oregon, died by suicide, local law enforcement officials announced on Saturday.

The suicide occurred during a firefight with law enforcement officers, who had arrived to disarm him, Douglas County Sheriff John Hanlin said at a press conference on Saturday.

Two Roseburg, Oregon, police officers and an Oregon state trooper exchanged fire with Harper-Mercer within minutes of arriving at the scene. The medical examiner subsequently ruled Harper-Mercer's death a suicide, suggesting that Harper-Mercer shot himself before law enforcement could kill him.

The sheriff confirmed that Harper-Mercer was enrolled in the class in which he opened fire, killing 9 people, among them classmates and the professor.

Hanlin also revealed that law enforcement found an additional handgun in Harper-Mercer's home, bringing the total number of firearms in his possession to 14.

To show just how short a period of time it took for the entire massacre and police response to transpire, the Douglas County Sheriff's Office released the following timeline of Thursday's events: