| MEXICO CITY
MEXICO CITY Factions of Mexico's brutal Zetas drug cartel are seen uniting behind the gang's second-in-command after Marines killed leader Heriberto Lazcano, a top official said on Wednesday.
Miguel Angel Trevino, a horse racing aficionado known as "Z-40", is expected to take over the cartel after Marines shot dead Zetas commander Lazcano on Sunday, said navy spokesman vice admiral Jose Luis Vergara.
Lazcano is the most powerful kingpin to fall in a six-year government battle against drug traffickers. Security analysts warned his death could spark a scramble for power and an escalation of violence in the cartel's northern strongholds.
The fall of other drug lords has spurred vicious battles in parts of Mexico that previously saw little violence, but Vergara said authorities do not expect a turf war between Zetas factions since Trevino, already a top leader, was a "natural" successor.
"We don't think that there will be violence due to a battle between them for power, since we think that Z-40 is definitely taking the lead," Vergara told Reuters.
"From what we know, the most bloodthirsty of them was Heriberto Lazcano, there's no doubt about that. I think his downfall should help curb the violence in our country," he said.
The Zetas are considered one of the two most powerful drug gangs in Mexico and have carried out some of the worst atrocities in a drug war that has killed some 60,000 people during President Felipe Calderon's six-year term.
Lazcano, known as "Z-3," was one of Mexico's most-wanted men. Only Joaquin "Shorty" Guzman, boss of the Sinaloa Cartel, would represent a bigger prize to the government.
Lazcano, an ex-soldier, became synonymous with the Zetas' gory brand of retribution, such as the beheading of rivals and a recent series of massacres where victims were chopped to bits.
Trevino, who was born in Nuevo Laredo on the Mexican side of the border with the United States, does not have a military background as many top Zetas leaders did, authorities say.
Along with two of his brothers, Trevino was charged with laundering drug proceeds in the U.S. quarter-horse racing circuit in June. U.S. Federal authorities accused Trevino and 13 others of pouring millions of dollars in proceeds from drug trafficking into the purchase, training and racing of American race horses across four U.S. states.
The U.S. State Department has offered a reward of up to $5 million for information leading to Trevino's capture.
Vergara said there were signs that a feud between Zetas leaders that erupted in late summer with a series of massacres appeared to have passed following the navy's capture of gang boss Ivan Velazquez late last month.
Velazquez was believed to be the Zetas' regional boss in a host of central and northern states, territory which includes the wealthy industrial city of Monterrey. Velazquez' gang had been fighting with Zetas loyal to Trevino, Vergara said.
"When they caught (Velazquez), the others accepted the authority of (Trevino), and Z-40 never had a problem with Lazcano," Vergara said.
Marines killed Lazcano and a bodyguard in a shootout in a village in northern Mexico on Sunday, and the navy said it did not know it had taken down the Zetas leader until after his body was snatched by an armed gang early on Monday.
Previously collected fingerprints identified the stolen corpse as Lazcano's, according to the navy.
(Writing by Michael O'Boyle; Editing by Sandra Maler)