Mexican authorities on Friday announced the arrest of the man they say directed the kidnappings of 72 Central and South American migrants found slain in northern Mexico last year.
Federal police said Edgar Huerta Montiel, 22, told them he led the capture of two freight trucks packed with undocumented migrants in the state of Tamaulipas, then killed 10 of the victims.
Huerta, described as an army deserter who works for the Zetas drug gang, allegedly told police he also ordered the kidnappings of six busloads of passengers in the rural town of San Fernando.
Captives were taken to safe houses and tortured for information, including whether they were working for the Gulf cartel, a rival gang, said Ramon Eduardo Pequeno, head of the anti-drug division of the federal police.
Tamaulipas, which borders Texas, has seen some of Mexico's worst violence amid fighting between the gangs and the inability of Mexican authorities to establish order.
The bodies of the 72 migrants were found in August on a ranch in San Fernando after one member of the group escaped. In the same area, authorities this spring found graves containing the remains of nearly 200 people believed kidnapped from buses headed toward the border. At least 21 suspects have been arrested in those slayings.
Migrants are frequently seized by gangs hoping to extort money from the victims' loved ones.
Some Mexican news media reported that Huerta had told police that more than 600 victims had been buried in makeshift graves, though authorities did not confirm that.
Huerta and his girlfriend were arrested Thursday in the northern state of Zacatecas.
Authorities said he was a top aide to Salvador Alfonso Martinez Escobedo, an alleged Zetas chief in Tamaulipas known as "Squirrel." The Mexican government has offered a reward of about $1.3 million for information leading to Martinez's capture.
Huerta also allegedly worked with another suspected crime boss, Martin Omar Estrada Luna, who was arrested in April by Mexican marines.