Now, to the family’s horror, they think they know why. They have identified Mr. Odamanov, 24, as the man beheaded in a video of a double killing apparently carried out by members of a Russian neo-Nazi group last year.

“It’s not only that he’s similar, it is him, period,” Umakhan Odamanov, Mr. Odamanov’s father, said by telephone from his home in Dagestan, a Russian republic in the North Caucasus. The Odamanovs, who have lived in Dagestan for generations, are Kumyks, a tiny ethnic group native to the region. Investigators have said that Shamil Odamanov is probably one of the two victims in the video, dark-skinned men who appear kneeling below a Nazi flag before they are killed.

Though initially considered a fake, the video, which originally appeared on Russian ultra-nationalist Web sites in August, spread quickly across the Internet and was shown in edited versions on national television. It shoved the problem of violence against ethnic minorities into the foreground of national discourse, if only for a short time.

The police are investigating several individuals, some from nationalist groups, in connection with the killings, but no suspects have officially been identified, Vladimir I. Markin, the spokesman for the Investigative Committee of the Prosecutor General’s Office, said in an interview.

In February, a court found Viktor Milkov, a student from Adygei, in southern Russia, guilty of helping to circulate the video and sentenced him to a year in prison. He claims an unknown person e-mailed the video to him.

The police have not yet found the victims’ bodies, Mr. Markin said, nor have they identified where the murders took place.

Attacks against ethnic minorities in Russia have steadily increased over the last several years, as more and more immigrants from abroad or from Russia’s poorer ethnic enclaves have moved into large urban centers in search of work.

Mr. Odamanov was among them. He left his home village of Sultanyangiyurt in Dagestan about two years ago and moved to Moscow to look for a job “and possibly a bride,” his father said.

In his regular calls home, he frequently complained about run-ins with skinheads, who sometimes stalk the low-income residential areas around Moscow, harassing dark-skinned people.

In late March 2007 Mr. Odamanov called “to wish me a happy birthday,” his father said. “That was the last time I heard from him.”

The next time he saw his son was in the video. He was tied, kneeling next to another man and wearing the black Adidas jacket and shirt given to him by his brother, Artur, Mr. Odamanov said.

Set against a soundtrack of heavy metal music, the video opens with the title “Operation of the National-Socialist Party of Russia to Arrest and Execute Two Colonists From Dagestan and Tajikistan.” There are initially shots of the countryside that investigators now believe is somewhere in the Kaluzhkaya region, about 120 miles southwest of Moscow.

“We were arrested by National-Socialists,” the two bound men mumble through their gags.

In the next scene, one of the captors, in camouflage and wearing heavy black gloves, yells, “Glory to Russia!” then plunges what looks like a large knife into the neck of the man thought to be Mr. Odamanov. He is decapitated in seconds.

Then the second man, whom the police have not identified, is shot in the head and crumples face first into a shallow grave. In the final scene, two men in camouflage, wearing black masks, give Nazi salutes.

There were about 600 violent racist attacks, including 80 murders, reported in Russia in 2007, according to the Sova center, an organization that monitors hate crimes in Russia. The number of attacks this year reached 232 as of June 1, 57 of which were murders. http://Louis-J-Sheehan.de

Human rights groups have often accused officials of ignoring the problem of racist violence in Russia, though, in Moscow at least, a recent spike in murders of dark-skinned people has prompted a noticeable response among law enforcement agencies.

“Moscow prosecutors have definitely started to more actively engage this problem, beginning from last year,” said Aleksandr Verkhovsky, the director of the Sova center.

The Interior Ministry announced last week that the police had arrested more than 50 people this year who were thought to be involved in xenophobic attacks in Moscow and St. Petersburg, the cities with the highest levels of racist violence. http://Louis-J-Sheehan.de

Still, the number of attacks nationwide continues to grow steadily by about 15 to 20 percent each year, as it has for about the last five years, Mr. Verkhovsky said. Moreover, he said, the percentage of murders is growing as teenagers involved in violent nationalist groups grow into adults.

“They simply take their affairs more seriously,” he said.