He was one of Mexico's most notorious drug traffickers, embroiled in fights to the death with rival gangsters and the Mexican military. His crude signature -- proclaiming him the "boss of bosses" -- showed up regularly next to the headless bodies of his foes.
So when Arturo Beltran Leyva fell dead Wednesday night during a frenzied gunfight with Mexican naval commandos, authorities declared a major blow struck against one of Mexico's meanest smuggling groups.
"This action represents an important achievement for the people and government of Mexico and a heavy blow against one of the most dangerous criminal organizations in Mexico," President Felipe Calderon said Thursday from Copenhagen, where he was attending an international climate conference.
"His death has dealt a crippling blow to one of the most violent cartels in the world," said Michele Leonhart, acting director of the U.S. Drug Enforcement Administration.
But amid the messy landscape of narcotics trafficking in Mexico, it is not clear what effect the kingpin's fall will have on his group or the wider drug underworld. The result could be more killing in Mexico if Beltran Leyva's absence sparks a succession war or inspires rivals to move in forcefully on his group's lucrative turf.
"It's an important step but, at the end of the day, you're not going to reduce the market," said Alberto Islas, a Mexico City-based security analyst. "You take out one guy and somebody else will take his place. But this is violent."
Mexico's attorney general, Arturo Chavez, acknowledged the possibility of more bloodshed, saying Beltran Leyva's killing could prompt his enemies in Sinaloa to act.
"The weakening of any cartel can be seen as an opportunity by another that is fighting for territory," Chavez said. "If they see [their rival] as weak, they will probably try to step up their actions to advance."
Chavez also warned of a possible succession fight inside the Beltran Leyva group.
About 15,000 people have died in Mexico since Calderon launched his crackdown on drug traffickers three years ago. Most of the slayings have resulted from fighting between rival gangs or power struggles within the groups. The Beltran Leyva gang has been a key part of that bloody panorama.
The group has been locked in a ferocious war with rivals led by Joaquin "Chapo" Guzman, a former ally, since early last year. Beltran Leyva held Guzman responsible for tipping off authorities who captured his brother Alfredo Beltran Leyva in January 2008.
That feuding, which has left hundreds dead, could intensify if members of Arturo Beltran Leyva's gang suspect Guzman's group of helping authorities track him down. Or the gang could retaliate directly against federal officials.
"I think we're going to see blowback," said Scott Stewart, vice president for tactical analysis at Stratfor, a global intelligence firm based in Austin, Texas.
The Beltran Leyva gang, which has been allied with another violent group, the Zetas, has battled rivals along the Pacific coast, a key smuggling corridor. Hand-lettered posters signed "the boss of bosses" have increasingly shown up alongside decapitated or dismembered bodies.
"Beltran Leyva was responsible for some of the most heinous acts of violence in Mexico's recent history," U.S. Ambassador Carlos Pascual said in a statement. "We congratulate the Calderon administration and the brave members of its military forces on this successful and highly significant operation."
The killing does not yet diminish the formidable financial resources or logistical reach of the Beltran Leyva gang, which U.S. authorities say has smuggled tons of cocaine into the United States from Colombia. But analysts agreed that it could prove a lasting blow.
Beltran Leyva, also known as "The Bearded One," is the first Mexican cartel leader slain by authorities since Tijuana kingpin Ramon Arellano Felix was shot by police in 2002.
That death and the arrest the same year of Arellano Felix's brother Benjamin marked the start of fraying in the Tijuana group, which has been beset by infighting and poaching by rival gangs.
Still, Mexican drug gangs have a long history of weathering the loss of their leaders, and it seemed unlikely that Beltran Leyva's death would disable his far-flung group any time soon. This month, the U.S. Treasury Department froze U.S.-based assets of 22 people and 10 companies with ties to the gang. Possible Beltran Leyva successors include another brother, Hector, who also goes by Mario Alberto and was already playing a leadership role. He was listed with Arturo Beltran Leyva this year among the country's 24 most-wanted drug traffickers.
Analysts said the man allegedly in charge of the gang's gunmen, Edgar Valdez Villarreal, also could vie for leadership.
Beltran Leyva, whose age is reported as 51, had been a main target of Mexican authorities since the arrest of his brother Alfredo last year, but he always managed to get away.
The trail had grown hotter in recent days.
DEA and FBI agents received information about a week ago on Beltran Leyva's whereabouts in the city of Puebla, southeast of Mexico City, and shared it with Mexican naval officials, according to a DEA official in Washington.
But Beltran Leyva and his bodyguards escaped a navy raid on the Puebla location, said the DEA official, who was not authorized to discuss the operation publicly.
Early the next morning, Mexican forces raided a Christmas party in the picturesque southern Mexico City suburb of Tepoztlan in search of cartel members. They arrested dozens of attendees and entertainers, including Latin Grammy-winning accordionist and singer Ramon Ayala.
Chavez said residents in nearby Cuernavaca reported the presence of heavily armed men in their neighborhood. The DEA official said U.S. and Mexican agents received information that the Beltran Leyva group had fled to a Cuernavaca high-rise.
Mexican forces moved residents, including teens at a party, to a gym in the complex. Helicopters circled low. Witnesses described a ferocious gun battle lasting an hour or more after troops charged in.
"What an experience," one resident told Mexican television. "Explosions! Grenades! Machine guns! I would never have imagined something like this happening in Mexico City, and much less Cuernavaca."
Six bodyguards and a Mexican marine also died in the shootout. The navy has played a growing role in the government's military-led drug war.
Authorities said one of the gunmen committed suicide to avoid capture. Three people were arrested.
Chavez said investigators identified Beltran Leyva's body based on statements by arrestees and comparisons with photographs. But he said they planned to conduct DNA tests.
Times staff writers Tracy Wilkinson in Mexico City and Josh Meyer in Washington contributed to this report.