Christopher Jordan Dorner
© The Associated Press
Former Los Angeles police officer Christopher Jordan Dorner is shown in this handout photo; a manhunt spread across southern California on Feb. 7, 2013 for Dorner, who has threatened to kill police and who is being sought in two weekend killings and is a suspect in an overnight shooting that killed one officer and wounded another.
Police in Southern California say they suspect that a fired cop is connected to the shootings -- one fatal -- of three police officers this morning, as well as the weekend slayings of an assistant women's college basketball coach and her fiancé in what cops believe are acts of revenge against the LAPD, as suggested in the suspect's online manifesto.

Former police officer Christopher Jordan Dorner, 33, who's also a former U.S. Navy reservist, has been publically named as a suspect in the killings of Monica Quan, 28, and her 27-year-old fiancé, Keith Lawrence, Irvine police Chief David L. Maggard said at a news conference Wednesday night.

"We are considering him armed and dangerous," Lt. Julia Engen of the Irvine Police Department said.

Police say the expert marksman shot at four officers in two incidents overnight, hitting three of them: one in Corona, Calif., and two in Riverside, Calif.

Sgt. Rudy Lopez of the LAPD said two LAPD officers were in Corona and headed out on special detail to check on one of the individuals named in Dorner's manifesto. Dorner allegedly grazed one of them but missed the other.

"[This is an] extremely tense situation," Lopez said. "We call this a manhunt. We approach it cautiously because of the propensity of what has already happened."

The Riverside Police Department said two of its officers were shot before one of them died, KABC-TV reported. The extent of the other's injuries is unclear. Police suspected a connection to Dorner.

"They were on routine patrol stopped at a stop light when they were ambushed," Lt. Guy Toussant of the Riverside police department said.

A badge and identification belonging to Dorner have been found in San Diego, according to San Diego police Sgt. Ray Battrick. Dorner's LAPD badge and ID were found by someone near the city's airport, and turned in to police overnight, The Associated Press reported.

Police around Southern California are wearing tactical gear, including helmets and guns across their chests. The light-up signs along California highways show the license plate number of Dorner's car, and say to call 911 if it is seen. The problem, police say, is that they believe Dorner is switching license plates on his car, a 2005 charcoal-gray Nissan Titan pickup truck.

Lawrence was found slumped behind the wheel of his white Kia in the parking lot of their upscale apartment complex in Irvine Sunday and Quan was in the passenger seat.

"A particular interest at this point in the investigation is a multi-page manifesto in which the suspect has implicated himself in the slayings," Maggard said.

Police said Dorner's manifesto included threats against members of the LAPD. Police say they are taking extra measures to ensure the safety of officers and their families.

The document, allegedly posted on an Internet message board this week, apparently blames Quan's father, retired LAPD Capt. Randy Quan, for his firing from the department.

"Your lack of ethics and conspiring to wrong a just individual are over," he allegedly wrote.

One passage from the manifesto reads, "I will bring unconventional and asymmetrical warfare to those in LAPD uniform whether on or off duty."

"I never had the opportunity to have a family of my own," it reads. "I'm terminating yours."

Dorner was with the department from 2005 until 2008, when he was fired for making false statements.

Randy Quan, who became a lawyer in retirement, represented Dorner in front of the Board of Rights, a tribunal that ruled against Dorner at the time of his dismissal, LAPD Capt. William Hayes told The Associated Press Wednesday night.

According to documents from a court of appeals hearing in October 2011, Dorner was fired from the LAPD after he made a complaint against his field-training officer, Sgt. Teresa Evans, saying in the course of an arrest she had kicked a suspect who was a schizophrenic with severe dementia.

After an investigation, Dorner was fired for making false statements.

"We have strong cause to believe Dorner is armed and dangerous," Maggard said.

Donner was a Navy reservist who'd just finished his military career as a lieutenant Friday. His only overseas deployment was to a Navy base in Bahrain. He also received a Rifle Marksman Ribbon and Pistol Expert Medal, meaning he received superior scores when he tested at the range.

Police say Dorner is 6-feet tall, and weighs 270 pounds. He has black hair and brown eyes.

Meanwhile, Cal State-Fullerton is still mourning the loss of their beloved assistant coach.

"There are really no words to convey the sadness that our program feels, that the young women who have had the privilege of working with such a bright and passionate woman," head coach Marcia Foster said earlier this week. "I want to especially send out condolences to Randal and Sylvia Quan, and her brother Ryan."

After college, Quan coached at Lutheran University in Thousand Oaks and has spent the past two years as an assistant coach at Cal State-Fullerton. The university has posted a memorial page on its sports website dedicated to Quan.

Lawrence was a business graduate who recently started working as a public-safety officer at USC.

The Associated Press contributed to this report.