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.

Dorner failed to properly check out of the Navy hotel on February 6, though he was not believed to still be on base, Fagan said.

February 6: Dorner named suspect, police announce threats

Authorities named Dorner a suspect in the Irvine killings. Authorities said he issued a "multipage manifesto" allegedly implicating himself in the slayings and complaining of his treatment in the LAPD.

Police said Dorner made violent threats against Los Angeles police officers. The force assigned officers to protect those connected to the threats.

February 6: Attempted boat theft in San Diego

Investigators said they believe Dorner tried to steal a boat from someone in San Diego. He failed and fled, LAPD Chief Charlie Beck said.

Later, a wallet is found containing Dorner's identification and an LAPD detective's badge near the San Diego airport, police said.

February 7: LAPD officer shot in the suburb of Corona

In Corona, Dorner fired at Los Angeles police officers who were assigned to protect a person connected to Dorner's threats, police said.

One officer was grazed in the head; the wound was not life-threatening, the LAPD said.

The officers returned fire, and Dorner fled.

"Due to damage to the police vehicle because of his gunshots, the officers were unable to pursue him," Beck said.

February 7: Officer killed, another shot in Riverside

Riverside police said two of its officers were shot in an ambush at an intersection. One died, and the other was taken to a hospital.

Authorities believe Dorner drove up to the officers' vehicle at a stoplight and fired with a rifle.

The officer who died, a 34-year-old Michael Crain, had been on the Riverside force for 11 years.

The other officer was seriously wounded but expected to make a full recovery, Riverside Police Chief Sergio Diaz said.

February 7: Police shoot two in Torrance in mistaken identity case

While searching for Dorner, police shot two people in Torrance in a case of mistaken identity, the Los Angeles police chief said.

LAPD officers assigned to protect someone who "was under the most serious levels of threat" saw a vehicle early in the morning that looked like Dorner's, Beck said. He said the vehicle was moving down a street with its lights off.