Castano relishes battle. “I’ve been shot four times,” he boasts, pushing up the sleeve of his T shirt to show the scar from a bullet that tore into his upper arm in 1994. “A grenade fragment almost ripped off my testicle. They got me to the field hospital in time to save it.”

His camp is strictly a private enterprise. The 32-year-old high-school dropout runs the Peasant Self-Defense Force of Cordoba and Uraba (ACCU), and fights to avenge the 1980 death of his cattle-ranching father at the hands of FARC rebels. “You could say that our methods aren’t in line with correct behavior - that we violate human rights,” he told NEWSWEEK last month in an exclusive interview at his mountain hideout in Uraba. His army’s victims include shopkeepers, mayors and farmers suspected of collaborating with the insurgents. Often they are kidnapped, tortured and then decapitated, earning Castano’s forces the nickname “the Head Cutters.”

Castano’s secret world isn’t easy to penetrate. The trip begins at dawn with a three-hour drive over a dirt road from Apartado, the main city in Uraba. Then there’s a one-hour horseback ride through jungle ravines and up denuded hills into Castano’s heavily guarded camp. Colombia’s most famous fugitive emerges from a tent to welcome us. He is short and compact, with a full-moon face and a crew cut. He wears an olive green T shirt and camouflage pants tucked into black rubber boots, a Beretta pistol in a holster on his belt. He exudes charismatic energy and the edginess of a man who has spent long years in hiding. “Is that photographer trying to take my picture?” he barks at a bodyguard, his voice raspy from Marlboros. “Better keep an eye on him.”

Since Castano took command of this army of vengeance from his brother in 1995, it has stepped up a brutal war against the leftist guerrillas. Castano has become a law unto himself on his home turf, a rich region where wealthy landowners and cocaine traffickers gladly support his force of 2,000 men. The fighting between paramilitary armies and left-wing rebels has driven 1 million Colombians out of their homes during the past decade. And the rising tide of extrajudicial killings by Castano’s men is making Colombia a bloody exception to the rule in Latin America, where such conflicts are largely a thing of the past. According to Human Rights Watch, a U.S. monitoring group, Castano’s forces executed more than 300 noncombatants between July and December 1996, and the number of killings is expected to rise sharply this year.

The Colombian government has been powerless to stop Castano’s rampage. President Ernesto Samper, weakened by allegations that he accepted $6 million in campaign funds from the Cali drug cartel, owes his political survival to the support of Colombia’s military. And top army officers, Colombian analysts say, have been reluctant to suppress Castano. Last December, in the face of rising violence by his forces, Colombia’s defense minister offered $1 million for Castano’s capture. But so far no one has seriously pursued the undisputed king of Colombia’s autodefensas, or paramilitary death squads.

In a country brutalized by 35 years of guerrilla conflict, many believe Castano’s methods offer the only real solution. His life story, a baroque tale of violence and revenge, has captured the nation’s imagination. And his populist reforms - including the distribution of 35,000 acres of land to local peasants - have won him support in the territory he controls.

Castano’s paramilitary career began near his mountain hideout. He grew up in the town of Amalfi in Cordoba, a violent region plagued for decades by FARC guerrillas. Carlos was the second youngest of 12 children of rancher Jesus Castano. In 1980 FARC rebels kidnapped the father and demanded $500,000 for his release. Carlos describes it as the defining moment of his life. “I was 15,” he says. “We mortgaged the finca, we sold the cattle and we raised $150,000. We paid it and then the guerrillas said, “Fine, but you’re short $350,000.’ Then my father was killed.”

The sons set out to get revenge. In 1981 Carlos and older brother Fidel signed on as guides for the army’s Bombona Battalion, which had begun to train the first civilian autodefensas. Overnight Fidel became the most feared death-squad leader in Colombia, going by the name “Rambo.” Between 1988 and 1990, investigators say, his hit squads massacred at least 151 people. In 1994 Fidel disappeared on an arms-buying trip to Panama. Colombian authorities believe he is on the run, but Carlos insists his brother was killed by guerrillas. “We recovered his body and buried him,” he says. Nor was Fidel the last Castano to disappear: three other brothers died fighting FARC, and sister Ruth was gunned down during a botched kidnapping attempt by the leftists.

With Fidel gone, Carlos assumed leadership of his army and began a drive to clean up its sinister reputation. Nowadays, he claims, suspects are brought before a secret tribunal presided over by three paramilitary judges. Two corroborative witnesses are required for a “conviction.” The tribunals, he maintains, have condemned only five people to death. Human-rights experts scoff at Castano’s claim to rule by law. After leftists attacked the village of Caicedo and killed a policeman last year, witnesses say, 20 troops in ACCU caps marched into town, rounded up four merchants, accused them of selling food to the guerrillas and shot them dead. Col. Carlos Velasquez, a former army commander in the region, describes ACCU justice: “A former guerrilla goes to a region and says to the paramilitaries, “We came here two years ago, and in that house they gave us coffee or food.’ That is sufficient to order their deaths.”

Castano insists he’s weary of war. His wife and two children live in Central American exile, and he’s been forced to send them videos of himself so they won’t forget him. “I want a normal life,” he says, escorting his guests to the horses. “I can’t educate my kids or watch them grow, for God’s sake. Is it a good thing that my kids see that a $1 million reward is offered for their father?” The visitors bid Castano goodbye and descend the sleep slopes on horseback. Sentries watch alertly from the ridge above. Castano’s freedom to stalk these rugged hills is as sure a sign as any that Colombia’s nightmare is far from over.