Suspected Mexico Drug Kingpin Arrested : Crime: He is captured in Tijuana. Authorities say he belongs to mob implicated in airport shootout that left Roman Catholic cardinal, 6 others dead.

A suspected drug kingpin, part of a family mob allegedly behind the Guadalajara shootout that left a Roman Catholic cardinal and six others dead last May, has been arrested, federal police announced Monday.

Francisco Rafael Arellano Felix, 44, was captured in the northern border city of Tijuana, where he and three brothers allegedly control a lucrative drug business. A dispute among warring drug cartels triggered the airport ambush in which Cardinal Juan Jesus Posadas Ocampo was killed, authorities believe. They say that the cardinal was a victim of mistaken identity in the attack.

Arellano is the second suspected drug boss arrested in the wide-ranging investigation that followed the shootout. He was wanted for trafficking drugs and arms, authorities said, although his role in the May slayings remained unclear. His three brothers are being sought for the cardinal’s murder.

The hunt for the three brothers will probably intensify in the wake of Arellano’s arrest, authorities said.

“It’s obviously a major breakthrough,” said one U.S. official. “The question is whether he’ll roll over, what they find out, what happens in the next few days.”

A terse statement from the Mexican attorney general’s office indicated only that Arellano was in custody “along with other people.” But press reports and sources indicated that he was captured sometime late Saturday or early Sunday at a Tijuana house and hustled onto a plane to Mexico City.

“Apparently, they had been looking at this particular place for a while,” a U.S. official said.

Mexican authorities refused to provide any details of his arrest.

The ambush in the airport parking lot in broad daylight on May 24 drew international attention to the spiraling violence associated with the competing mafias who control the multibillion-dollar trade in cocaine, marijuana and heroin destined for the thriving U.S. markets.

Shortly after the shootout, authorities detained an alleged major rival of the Arellano gang, Joaquin (El Chapo) Guzman. According to official accounts, Guzman was the intended target of the assassination squad.

The rival gangs were feuding about control of the Tijuana drug trade, according to law enforcement officials in the United States and Mexico. Tijuana, the most populous city along the U.S.-Mexico border, is the gateway for much of the northbound drug traffic, authorities believe.

Cardinal Posadas, his driver and five others died in a spray of automatic weapons at the Guadalajara airport, Mexico’s second busiest.

Some in Mexico have questioned how the cardinal could have been mistaken for the supposed drug boss. The cleric, who was 66 and one of Mexico’s two cardinals at the time of his death, had spoken out publicly about the danger that narcotics and guns posed to society.

Eight of the 15 suspected triggermen were taken into custody in the weeks following the shootout. Seven remain in custody; one died in jail.

The failure of Mexican authorities to arrest the Arellano brothers since the shooting--despite the posting of a $5-million reward and a nationwide manhunt--has provoked fierce criticism of law enforcement efforts here.

After the cardinal’s killing, some members of the hit team--including at least one of the Arellano brothers--left Guadalajara aboard a Tijuana-bound commercial flight that airport authorities held for 20 minutes so that the men could board it, according to law enforcement sources.

And critics have long alleged that major drug traffickers enjoy virtual impunity in Mexico, often employing federal police officers as their bodyguards and henchmen.

Denunciations of the authorities have sharpened as drug-related violence has escalated, reaching the capital last month with a gangland-style hit that left five dead in a popular restaurant.

But Atty. Gen. Jorge Carpizo MacGregor has insisted that the government has made progress in its declared war against the drug trade.

“The problem is that, really, the traffickers have managed to buy the police,” Carpizo, a former human rights advocate, said in an interview shortly after the cardinal’s slaying.

In the aftermath of the shooting, authorities fired or jailed dozens of police officers with alleged ties to the drug barons.

Mexican authorities insisted as recently as October that they were closing in on the Arellano gang.

According to official accounts, police had confiscated numerous Arellano properties, including a chain of drugstores, 118 houses, five real estate firms and six other businesses. Lawmen also said they had confiscated arms caches, cellular telephones, vehicles and almost $4 million in cash belonging to the brothers. Much of the booty was seized during raids in the Tijuana area.

Arellano ranked below his younger brother, Benjamin, the reputed leader, in the family drug hierarchy, officials said. Another brother, Ramon, is accused of leading the gunmen in the Guadalajara incident.

Francisco Arellano spent much of his time in the coastal city of Mazatlan in Sinaloa, the Arellanos’ home state and a known bastion of drug activity. He owned extensive property in the area, including a discotheque, officials said, and allegedly laundered the cartel’s money through Mazatlan.

He is wanted in San Diego on a 1980 warrant for failing to appear on charges of selling half a kilo of cocaine, according to U.S. officials.