The manhunt may be over for a former Los Angeles police officer accused of shooting five police officers -- killing two -- and slaying two other people.

Christopher Jordan Dorner, 33, had threatened to target law enforcement officers in retaliation for being fired more than four years ago, authorities say.

Here's a timeline of the case:

2001-2002: Dorner graduates college, joins Navy

Dorner grew up in Southern California before attending Southern Utah University, where he was a running back for the school's football team. He graduated with a degree in political science in 2001.

He joined the Navy after college, receiving a commission as an ensign in July 2002. He trained in river warfare units and eventually was rated as a rifle marksman and pistol expert, according to Pentagon records.

2005-2006: Dorner starts LAPD career

Dorner enrolled in the Los Angeles Police Academy in February 2005. After graduation, he spent a few months on the streets as a trainee.

2006-2007: In Iraq with the Navy

The Navy recalled Dorner to active duty, and he served a 2006-2007 stint in Iraq guarding oil platforms.

2007-2011: Return to LAPD, termination and appeals

After his tour in Iraq, Dorner returned to the Los Angeles Police Department in 2007. Shortly after his return, he reported excessive force by a fellow police officer in July 2007.

In a letter allegedly written by Dorner and provided to CNN this week, he said he was relieved of his duties in 2008 after he made the report against the other officer. The letter was provided to CNN by an LAPD source after this week's manhunt began.

Dorner tried to get his job back in 2008, but the LAPD's Board of Rights rejected his appeal. He eventually took the case to court, but a judge ruled against his appeal in October 2011.

February 1: Dorner leaves Navy

Dorner was honorably discharged from the U.S. Navy Reserve as a lieutenant, according to Pentagon records.

February 3: Two killed in Irvine

Two people -- Monica Quan, 27, and her fiance, Keith Lawrence -- were killed in Irvine, California, while sitting in a vehicle at a parking structure, authorities said. Quan was the daughter of former LAPD Officer Randal Quan, who, it is claimed in the letter, bungled Dorner's LAPD termination appeal.

February 5: Dorner at Navy hotel in San Diego

Dorner checked into the Navy Gateway Inns and Suites on San Diego's massive naval base, Navy Cmdr. Brad Fagan said. Dorner probably had access to the hotel from having been honorably discharged, which would mean he would have an ID card, Fagan said.