In August, the Beltrán Leyva cartel lost their leader, Edgar “La Barbie” Valdez Villarreal. On Wednesday, the cartel fighting to control a large territory south of Mexico City suffered another blow after their new leader was captured by federal police.
Carlos Montemayor was arrested in Mexico City on Tuesday with the help of the U.S. Drug Enforcement Administration and with information obtained after Valdez's arrest on Aug. 30, said Ramón Pequeño, the federal police anti-narcotics chief.
Montemayor, whose daughter is married to Valdez, took over the splintered faction after "La Barbie" was caught, Pequeño said.
Authorities say Valdez, a Texas native who faces possible extradition to the United States, tried to seize control of the gang after boss Arturo Beltrán Leyva died in a December shootout with marines.
The battle within the cartel was marked by decapitations, bodies hung from bridges and shootouts in the area from Acapulco to the picturesque city of Cuernavaca.
Montemayor also told police that his faction was responsible for kidnapping and killing 20 Mexican tourists in Acapulco, mistaking them for members of the rival La Familia cartel, Pequeño said.
The men, many of them mechanics and some of them related to each other, were kidnapped in September while traveling in cars with license plates from their home state of Michoacán -- the birthplace of La Familia.
The bodies of the men were found in a mass grave outside Acapulco earlier this month.
Pequeño said Montemayor joined the Beltrán Leyvas in 2003 after meeting cartel leader Sergio Villarreal Barragán, a cousin of Montemayor's wife. Villarreal, who is not related to "La Barbie," was captured in September.
Montemayor started out smuggling about 60 kilograms of cocaine a month to the United States, hidden in trucks, Pequeño said. At the time, the Beltrán Leyvas were aligned with the powerful Sinaloa cartel.
The steady dismantling of the Beltrán Leyva gang has been one of the biggest successes in President Felipe Calderón's drug war since he deployed tens of thousands of federal police and soldiers in 2006 to fight Mexico's cartels in their strongholds.
But the increasing splintering of the gangs has come with a bloody cost. An unprecedented 28,000 people have been killed in drug-related violence since 2006, and the fighting has become more horrifying.
An opinion poll released this week found 49 percent of Mexicans believe the government's drug war has been a failure, compared to 33 percent who said it has been a success. The rest had no opinion.
The Mitofsky polling firm surveyed 1,000 adults face-to-face from Oct. 28 to 31. The poll, conducted for the citizens' group Mexico United Against Crime, has a margin of error of plus or minus 3.1 percentage points.
The AP Contributed to this report.