ARGUN, Russia — When the man in the fancy four-wheel drive asked Din-Magomed to teach his son how to swim, it seemed like an innocuous enough request, and the boy readily agreed.

But the 13-year-old would spend the next two days being tortured by members of one of Chechnya’s most infamous Russian-backed law enforcement units.

Such treatment is commonly meted out to those accused of collaborating with Chechnya’s rebels. But Din-Magomed’s alleged crime was much more mundane: he had been accused of stealing a mobile phone and a pair of earrings from the man’s car. Din-Magomed says he was guilty of nothing more than sneaking out of his house for an illicit swim at a nearby lake on a hot day last August.

When he was released, Din-Magomed had suffered a fractured skull, concussion, chest trauma, and bruising. Nearly eight years into the second Chechen war, Russia’s most rebellious province remains a deeply troubling place. Bearded militiamen, dressed in Islamic skullcaps and American military fatigues, roam through the partially rebuilt ruins of Chechnya’s cities carrying out the thuggish whims of an indigenous administration imposed by the Kremlin.

Their victims are dragged off the streets, or they simply vanish from their homes. Officially, the number of reported incidents has been falling in the past two years.

But according to human-rights bodies, this is only because many victims’ relatives are too frightened to report disappearances.

Some things in Chechnya are changing, however — though not for the better, activists say. At what is expected to be a lavish ceremony today, Chechnya’s alpha warlord, Ramzan Kadyrov, will be sworn in as the republic’s president.

An amateur boxer who keeps a lion as a pet, the 30-year-old has been accused of presiding over a culture of torture and secret prisons — it is even alleged that he once used a blow torch on a rival. Perversely, Mr. Kadyrov’s appointment could be good news for the family of Din-Magomed and their quest for justice.

Although he is a Kremlin appointment, the president has accused ORB-2 of serious abuses and has signaled in the past month that he wants to shut it down.

Not that Mr. Kadyrov has suddenly become an unlikely champion of human rights. His own 8,000-strong private army, known as Kadyrovtsi, is perhaps the worst offender among the loyalist militias. A more likely reason, analysts say, is that the president regards ORB-2 as a rival he cannot control.

The Kadyrovtsi’s job is to root out separatist fighters. But most of the militia are ex-rebels themselves and activists claim that they have sold protection to prominent separatists. “Their victims aren’t rebels, but ordinary people,” said a Russian activist who travels to Chechnya.

One such victim is Samai Abzuyeva. She says the Kadyrovtsi tortured her son, Abdulbek, to death a year ago to wrest control of his second-hand car dealership.

Enraged that Mrs. Abzuyeva has tried to seek justice, the militiamen, working with Abdulbek’s widow who wants to force her from her apartment, have turned their anger on the 76-year-old grandmother.

“I’m begging you to help me punish these people,” she told the Daily Telegraph.