After Sanchez Arellano apparently tried to kill one of Garcia's top gunmen outside a Rosarito Beach taco stand, Garcia's squad retaliated by killing five of Sanchez Arellano's associates and leaving their dismembered bodies in cars outside the same taco stand, law enforcement officials said.

The government, meanwhile, seems helpless to stop the killings. Police officers who have not been lured away to work for Garcia as drivers, lookouts and hit men are paralyzed with fear. Garcia is said to possess a list with every cop's address and phone number. More than one police officer has answered his phone to threats from a man identifying himself as Garcia.

Other times, there is no warning -- as in January, when gunmen surrounded the home of Deputy Police Chief Margarito Saldaña Rivera and opened fire, killing him, his wife and two daughters. Authorities blame Garcia for the slaying.

Officers stationed in Garcia's stronghold in eastern Tijuana put tape over the numbers on their cars and patrol in groups of two or three cruisers. If they see a convoy of Ford F-250s and Cadillac Escalades -- the drug gangs' vehicles of choice, often stolen from California -- they go the other way.

"We're scared," said one police officer. "There's no way U.S. cops would work under these conditions."

The ineffectual response has exposed the disarray of law enforcement's anti-drug efforts in Baja California, where relations between federal and local forces are marked by distrust and there is little sharing of intelligence.

Garcia, who is said to move constantly, and always with armed guards, seems to mock police efforts. One of his lieutenants, Raydel Lopez Uriarte, nicknamed Muletas, or crutches, gives his squad uniforms inscribed with the letters FEM: the Spanish initials for Special Forces of Muletas. The uniform patches feature a skull and crossed crutches, for the death and crippling injuries they leave in their path.

Garcia's alleged tactics have earned him at least one potent enemy.

In October, after a Mexican soldier was killed in a clash in which four gunmen also died, Tijuana's top military commander, Gen. Alfonso Duarte Mugica, mentioned Garcia's name at a news conference, signaling that the alleged crime boss was in his cross hairs.

About three weeks later, hundreds of soldiers and federal agents fanned out across neighborhoods believed to be Garcia's stronghold. For 24 hours, the killings stopped. Then, more than 40 people were slain over three days.

Three were police officers. They had been decapitated along with six other people, whose corpses left no doubt who was responsible: Their bodies, placed head to toe, had been arranged to spell out "3 L." Tres Letras.