(ABC NEWS) -- The fired ex-California cop who set off a region-wide manhunt after allegedly shooting three police officers Thursday morning -- one fatally -- had initially gone to a yacht club near San Diego where police say he attempted to steal a boat and flee to Mexico.
Police say that former police officer Christopher Jordan Dorner, 33, who officials believe posted an online manifesto outlining his plan to "terminate" his former colleagues and their families, is armed with a long gun and might have several other guns and high-capacity magazines. He is also believed to have access to military uniforms because he has served in the Navy.
"We are considering him armed and dangerous," Lt. Julia Engen of the Irvine Police Department said.
Police allege that he went to the yacht club Wednesday night at Point Loma, Calif., near San Diego to steal the boat. He aborted the attempted theft when the boat's propeller became entangled in robe, law enforcement officials said. It was at that point he is believed to have headed to Riverside, where he allegedly shot two police officers.
"He pointed a handgun at the victim [at the yacht club] and demanded the boat," Lt. David Rohowits of the San Diego 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 the 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 other is in stable condition with two gunshot wounds, police say.
"They were on routine patrol stopped at a stop light when they were ambushed," Lt. Guy Toussant of the Riverside police department said.
In the manifesto Dorner published online, he threatened at least 12 people by name, along with their families.
"Your lack of ethics and conspiring to wrong a just individual are over. Suppressing the truth will leave to deadly consequences for you and your family," Dorner wrote in his manifesto.
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.
Los Angeles Police Department Chief Charlie Beck said today that 40 protective details have been deployed to protect officers and their families.
"We are taking all measures possible to ensure safety of our officers and their families," he said.
Dorner is also believed to be responsible for 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 his online manifesto.
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.
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.
Donner was also 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.
A Navy official confirms Naval Base Point Loma is on lockdown.
Police say Dorner is black, 6-feet tall and weighs 270 pounds. He has black hair and brown eyes, and believed to be driving the Nissan pickup truck.
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.
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The Associated Press contributed to this report.