When he was deported from the U.S. to Mexico for the third time, Martin Estrada Luna was a high school dropout with a rap sheet of petty crimes like burglary.
Less than two years later, Mexican authorities say, he has transformed himself into a drug baron known as El Kilo, the leader of a ruthless cell of the Zetas gang who masterminded the mass killings of more than 250 people. He is now under arrest in Mexico City.
Mexican prosecutors have not presented any evidence publicly to support their claim that he was responsible for the deaths of 72 migrants in August and 183 people months later. The Mexican government often announces big arrests immediately after high-profile crimes, but according to its own statistics, three-quarters of those initially accused as drug traffickers or assassins are let go without charges.
Whether he was a big player or not, Estrada Luna appears to have succumbed to a cross-border crime culture that is growing as hundreds of thousands of deportees with criminal backgrounds are dumped in Mexico. Under a tough-on-crime immigration crackdown, half of the 393,000 people deported from the United States between October 2009 and September 2010 were convicted criminals, with crimes that could have ranged from minor drug offenses to murder.
There are seldom arrest warrants to hold the ex-convicts in Mexico, so they are let loose into a lawless border land increasingly run by drug lords eager to train recruits in violent tactics.
In San Fernando, Tamaulipas, neighbors are too scared to talk about the 255 bodies found executed in groups or buried in pits. State police are afraid to venture onto the backroads where the Zeta drug gang hides out, and even federal police cower for protection in an understaffed base.
Ranchers complain that their isolated spreads are being taken over by Zeta gunmen, who Mexican officials say are recruited through violence and turned into killing machines. Tamaulipas state Interior Secretary Morelos Canseco said there has been a "terrible upward spiral" in brutality since 2010, when war broke out between the Zetas and their old allies, the Gulf Cartel.
"You get status in these groups based on who can do the worst thing, who can do what nobody dares to do. It is like a competition in perversity," he said. "First they would steal cars and let the people go, but later they would steal the car and take the women. ... After that, they steal the cars, take the women, and kill anybody who resisted."
It was here where Estrada Luna arrived, a 34-year-old tattooed member of the Norteno gang, known as El Kilo, a measure of weight, because of his more than 6-foot, 200-pound frame. Estrada Luna could not be reached in custody, and does not have a lawyer of record.
Estrada Luna was born in Mexico and grew up in Tieton, a tiny Washington-state farm town dominated by the apple industry. His mother lived in Laredo, Texas, and his stepfather was a U.S. citizen.
People who knew Estrada in Washington state said he was trouble, but don't believe he could have killed more than 250 people.
"We got along. He had never, ever mouthed off to me," said Tieton Police Chief Jeff Ketchum, who recalled Estrada as a product of a broken family, crashing on friends' couches and finding petty trouble. "He was a leader, in a bad sense, obviously, but I don't believe he actually did (the murders)."
The U.S. deported Estrada for the first time in 1998, after a seven-month prison term for burglary and weapons charges. He was deported a second time after a jail stint that included a jailbreak by four other inmates _ Estrada himself was too large to fit through the hole they had broken in the cell ceiling.
In January 2009, he was deported for the final time from San Diego's San Ysidro border crossing, after a prison term in Herlong, Calif. for re-entry after deportation. His mother, Ofelia De La Rosa, who works as a housekeeper at a hotel in Laredo, Texas, said she hadn't seen her son in "more than a year." She refused to answer any other questions.
He was dumped in Tijuana, Mexico. He made his way east to the violent border state of Tamaulipas, where he had family. There, local police say, he got a job as a "burrero," running drug shipments for the Zetas up from the lower Gulf coast to the border. While that seems a quick rise, one U.S. official speaking on condition of anonymity said the government crackdown and war with the Gulf cartel have caused so many casualties in Zeta ranks that recruits become local leaders in a year or two.
From his apparent base in a walled, palm-lined compound in the La Peregrina slum on the outskirts of the Tamaulipas state capital, Ciudad Victoria, Estrada Luna began running a network of street-level drug dealers, police said.
In the first massacre in the area in August last year, 72 mainly Central American migrants were asked whether they wanted to work for the Zetas. When they refused, they were gunned down.
In March, possibly also in an attempt at forced recruitment, the Zetas kidnapped passengers off passing buses, took them into the backwoods, killed them and buried them dozens at a time in mass pits, police said. No ransom demands were ever received.
Tamaulipas official Canseco acknowledged that "a very large number" of the victims died of blows to the head with a heavy object, and that a sledgehammer was found at one of the sites. But he could not confirm whether they were forced to fight.
On April 16, Estrada Luna was arrested at his house by Marines. A Mexican Navy official who was not authorized to be quoted by name said that once in custody, Estrada Luna was unusually violent, struggling with his guards and attempting to slip off his handcuffs.
"It was as if he couldn't get it through his head that he was caught," said the Navy official.
While some residents of the La Peregrina slum said they'd never seen or heard of "El Kilo," others remembered him as a drug trafficker with a violent streak _ but hardly the ringleader that authorities have depicted.
The owner of a small food store said he came in on two or three occasions just before his arrest to buy single cans of beer, while a companion picked up bags of chips or snack foods. She said he was silent, bulky and brooding, but did not seem threatening.
The store owner _ who asked that her name not be used for fear of reprisals _ said Estrada Luna once asked her for two small bags of bicarbonate of soda, a remedy frequently used in Mexico for stomach ailments. She heard him tell a friend, "I'm going to use it for mixing." Thinking he had an upset stomach, she suggested he try mixing Coca-Cola with lime juice, another folk remedy.
"He just smiled at me, and then I realized...it was for mixing something else," she said, gesturing to her nose. She suggested a real drug-gang chief wouldn't be buying his own beer and bags of chips or cutting his cocaine with cheap bicarbonate.
But another shop owner described how he came into her shop one day not long ago with a girl whose throat was ringed by severe bruises. She said she overheard Estrada Luna tell a friend, "I almost killed her, but I relented."
People still fear his gang in the dirt streets of La Peregrina, an area so rough that it is patrolled not by police but by convoys of soldiers in pickup trucks, guns at the ready.
"They are still here. It's not safe," said one man as he stood near the compound where El Kilo was arrested. Nervously eyeing a man dressed in military-style clothes down the dirt street, he said, "They haven't gone away."
Some police sources suspect federal authorities may have arrested Estrada Luna because he was a top contender to take over local leadership after other Zeta bosses fled or disappeared.
In San Fernando, none of the police, local officials or residents said they had seen or heard of "El Kilo," even people who lived less than a mile from one of the pits used to dump the bodies.
"If I answer that question, I'd be found the next morning with my throat slit," said one heavyset, gregarious store owner sitting on a metal chair outside his business.
Police sources suggest Estrada Luna wasn't well known because he took drug shipments through San Fernando rather than basing himself there. But many people would be too afraid to say they had seen him in any case; even Mayor Tomas Gloria doesn't allow himself to be videotaped or photographed during interviews. Asked if he knew of El Kilo, Gloria said no, but added that "people in San Fernando have learned to be discreet."
Even with a heavy military presence, life is alarmingly normal in the center of San Fernando; people stroll through a sun-washed central plaza and eat ice cream. But that ends abruptly on the outskirts of town, where an armed convoy of several state police vehicles refused to venture down a dirt trail that leads to a mass grave.
"They could be anywhere in there, and we would just be targets," said the commander of the convoy.
At one of the pits, the marks of backhoes were still visible, like the ones authorities say the Zetas used to cover the corpses.
Only the Mexican army and Marines can enter here. Federal police say that sometimes their lonely base on the outskirts of town has been surrounded by convoys of taunting Zetas who send them death threats over radio frequencies.
Those who knew Estrada Luna wonder what happened to him in this borderland that has turned into a magnate for drifters, deportees and thousands of migrants with criminal backgrounds. Authorities say even Central American Mara street gang members wander there and end up working for the Zetas.
Melva St. George, a Tieton, Washington woman whose uncle married Estrada Luna's mother, described "El Kilo" and his brother this way: "they were good kids, but they just started getting into trouble as they got older."
Estrada calls himself a "proud parent" on his MySpace page _ relatives say he has at least two children. As his hero, he lists "my jefita" - Mom.
Associated Press writer Elliot Spagat contributed to this report from San Diego.