1,000 clues and lots of frustration in manhunt for ex-LAPD officer LAPD media relations spokesman Andy Neiman briefs the media in the latest in the search for ex-LAPD officer Christopher Dorner, suspected of killing three people. LAPD officials admitted Tuesday that the manhunt for ex-cop Christopher Dorner -- now in its sixth day -- has turned "frustrating" as they sift through a mountain of clues, including a video that may show the suspect stocking up on scuba gear before the killing spree. Former LAPD officer Christopher Dorner, who is suspected of killing three people in a revenge rampage. "With a thousand clues or tips, you have to prioritize," LAPD Lt. Andy Neiman said at a briefing. Dorner, 33, may not even be in the United States any longer. Police confirmed that they are looking into the possibility he fled to Mexico -- the destination he mentioned when he tried to steal a boat in San Diego last Wednesday. Dorner, who was in the Navy Reserves, is accused of killing a retired captain's daughter and her fiance in Irvine on Feb. 3 and charged with killing a police officer in Riverside, Calif., last Thursday. Investigators say he is seeking revenge for being fired from the LAPD in 2008. A manifesto posted online details his grievances and sets forth a plan to execute police figures and their families. Police have recovered his burned-out truck near the Big Bear Lake ski resort, but a door-to-door search there -- along with a $1 million reward -- has turned up no sign of him. "It is frustrating," Neiman said. We are hopeful that these investigative leads will lead to a conclusion. Among the newest leads, a video that was posted on TMZ that appears to show Dorner purchasing scuba equipment at Sport Chalet in Torrance, Calif., on Feb. 1. Neiman said police had not nailed down if it was Dorner and could not say why he would be buying underwater gear. A criminal complaint filed in federal court last week says Dorner may have fled to Mexico, but provides no specifics. It also revealed that investigators have been tracking an associate of Dorner -- someone with the initials J.Y. -- whose family has property not far from where Dorner's vehicle was abandoned and torched. NBC News' Jessica Benson contributed to this report. U.S. Customs and Border Protection officers check vehicles approaching the U.S.-Mexico border in their search for Christopher Dorner.