This is an archived article that was published on sltrib.com in 2013, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Makhachkala, Russia • Russian agents placed the elder Boston bombing suspect under surveillance during a six-month visit to southern Russia last year, then scrambled to find him when he suddenly disappeared after police killed a Canadian jihadist, a security official told The Associated Press.

U.S. law enforcement officials have been trying to determine whether Tamerlan Tsarnaev was indoctrinated or trained by militants during his visit to Dagestan, a Caspian Sea province that has become the center of a simmering Islamic insurgency.

The security official with the Anti-Extremism Center, a federal agency under Russia's Interior Ministry, confirmed the Russians shared their concerns. He said that Russian agents were watching Tsarnaev, and that they searched for him when he disappeared two days after the July 2012 death of the Canadian man, who had joined the Islamic insurgency in the region. The official spoke only on condition of anonymity because he was not authorized to speak to the news media.

Security officials suspected ties between Tsarnaev and the Canadian — an ethnic Russian named William Plotnikov — according to the Novaya Gazeta newspaper, which is known for its independence and investigative reporting and cited an unnamed official with the Anti-Extremism Center, which tracks militants. The newspaper said the men had social networking ties that brought Tsarnaev to the attention of Russian security services for the first time in late 2010.

It certainly wouldn't be surprising if the men had met. Both were amateur boxers of roughly the same age whose families had moved from Russia to North America when they were teenagers. In recent years, both had turned to Islam and expressed radical beliefs. And both had traveled to Dagestan, a republic of about3 million people.

The AP could not independently confirm whether the two men had communicated on social networks or crossed paths either in Dagestan or in Toronto, where Plotnikov had lived with his parents and where Tsarnaev had an aunt.

After Plotnikov was killed, Tsarnaev left suddenly for the U.S., not waiting to pick up his new Russian passport — ostensibly one of his main reasons for coming to Russia. The official said his sudden departure was considered suspicious.

In an August interview with the Canadian newspaper National Post, Vitaly Plotnikov said his son, who was 23 when he died, had converted to Islam in 2009 and quickly became radicalized. But he said he fully understood what his son was up to in Russia only when he received photographs and videos after his death.

In one photo, a smiling William Plotnikov is shown posing in the woods, an automatic rifle slung over his shoulder and a camouflage ammunition belt around his waist. In the videos, the younger Plotnikov talked openly of planning to kill in the name of Allah.