New details in federal court records provide clues as to why authorities developed "probable cause" that a former police officer wanted in a deadly shooting rampage may have fled to Mexico as a massive manhunt was gearing up to catch him.

Christopher Jordan Dorner, 33, a former Los Angeles Police Department officer, has eluded authorities since Wednesday night when he was named as the suspect in the slaying of an Irvine couple, a crime that triggered a wave of violence and a law enforcement dragnet across California and Nevada.

Dorner allegedly attempted to steal a boat in San Diego and, after subduing the captain, said he was taking the vessel to Mexico, according to an affidavit filed with a criminal complaint in federal court in Los Angeles. Dorner is accused of telling the captain that he could recover his boat in Mexico.

DOCUMENT: Feds say Dorner may have fled to Mexico

"The attempt failed when the bow line of the boat became caught in the boat's propeller, and the suspect fled," according to the affidavit by inspector U.S. Marshal Craig McClusky.

After authorities interviewed the boat captain early Thursday, they found Dorner's wallet and identification cards "at the San Ysidro Point of Entry" near the U.S.-Mexico border, the court records show. That same day, a guard at the Point Loma Naval Base told authorities he had spotted a man matching Dorner's description trying sneak onto the base, according to the court records.

Federal authorities told The Times on Monday night that the court papers, filed late last week, reflected their thinking at the time, but they stressed that Dorner could be anywhere.

PHOTOS: Manhunt for ex-LAPD officer

On Monday, hundreds of officers across Southern California were searching for the fugitive. Investigators said they were sifting through 800 clues, which began pouring in after authorities announced a $1-million reward for information leading to Dorner's capture.

The possibility of Dorner receiving help by an associate was raised in the court records. In his affidavit, McClusky said investigators with the Marine Corps and San Bernardino County Sheriff's Department were conducting a surveillance operation of an Arrow Bear property owned by a family member of the associate Thursday and discovered a burning vehicle nearby that matched the gray Nissan pickup truck used by Dorner.

The burning vehicle led to a large-scale search in the San Bernardino Mountains near Big Bear as law enforcement teams scoured the snow-covered terrain looking for Dorner. The effort, which has used search dogs and helicopters with infrared devices, was scheduled to continue Tuesday, authorities said.

TIMELINE: Manhunt for ex-LAPD officer

A former reserve Navy lieutenant, Dorner allegedly threatened "unconventional and asymmetrical warfare" against police in a lengthy manifesto that authorities say he posted on Facebook. The posting named dozens of potential targets, including police officers, that Dorner allegedly threatened to attack, according to authorities.

The records state that the manifesto was discovered by authorities Wednesday, three days after the slaying of the two Irvine victims, one of them the daughter of a retired LAPD captain whom Dorner blamed in part for his firing from the force in 2009.

The federal document also provides new details on Dorner's alleged attacks against officers in Riverside County early Thursday.

The first shooting was in Corona after an eyewitness reported a person matching Dorner's description at a gas station to an LAPD officer "who was detailed to the area to protect one of the officials whom Dorner had threatened," according to the court records.

"When the officer drove by the gas station, the suspect exited his vehicle and fired an assault rifle at the officer, hitting the officer's vehicle," according to the court records.

The LAPD later said the officer received a grazing wound.

About 30 minutes later, Dorner opened fire on Riverside police officers "who were in the area searching for Dorner," the document said. The account conflicts with a statement provided to the media by Riverside police officials, who said the officers were simply stopped at a red light and not looking for Dorner.

ALSO:

Dorner manhunt: Despite reward, no new signs of ex-cop

Dorner manhunt: conflicting testimony in ex-cop's firing case

Dorner manhunt: Riverside D.A. files murder charges against ex-cop

-- Andrew Blankstein and Robert J. Lopez

Photo: Christopher Jordan Dorner and former L.A. Police Chief William J. Bratton.