Five days into the search for fugitive ex-cop Christopher Jordan Dorner, authorities hope a $1-million reward that will be announced Sunday could jump-start the case.

The frustrating search has spanned from Riverside to Corona to Big Bear to Point Loma in San Diego. There have been numerous false starts, but officials say the heightened publicity has not brought them closer to making an arrest.

Officials said Sunday the search in Big Bear was winding down.

PHOTOS: Manhunt for ex-LAPD officer

On Sunday morning, authorities received a tip that Dorner may have been spotted down the mountain in San Bernardino, forcing the evacuation of an apartment complex, but it turned out to be a false alarm.

The manhunt for Dorner began last week after the 33-year-old former Los Angeles police officer and Navy veteran allegedly began a deadly campaign that has left three people dead and two others injured. Dorner is believed to be upset over his firing from the police department in 2009.

Dorner's Nissan Titan pickup was found Thursday morning engulfed in flames on a mountain road in the Big Bear area, and law enforcement officials have since focused their search efforts there.

TIMELINE: Manhunt for ex-LAPD officer

Los Angeles Police Chief Charlie Beck announced he was reopening the investigation into the firing of Dorner from the Police Department, the event that apparently sparked his vengeful campaign.

Beck said he was reopening the investigation "not to appease a murderer" but to assure the public his department is fair and transparent. He said he wanted to protect an "increasingly positive relationship with the community" that the LAPD has developed over the last few years.

"I am aware of the ghosts of the LAPD's past and one of my biggest concerns is that they will be resurrected by Dorner's allegations of racism within the department," Beck said in a prepared statement. "...Therefore, I feel we need to also publicly address Dorner's allegations regarding his termination of employment."

DOCUMENT: Chief Beck's statement regarding Dorner

Dorner was stripped of his badge in 2009 after a police disciplinary board found him guilty of making false statements against his training officer, Teresa Evans. In August 2007, Dorner accused Evans of kicking a mentally ill man during an arrest in San Pedro.

The internal affairs investigation concluded Evans had not kicked the man and Dorner was lying.