The suggestion that more went on in the Boston Marathon bombing plot than just two brothers and their own grievances will gain traction with this new arrest by federal investigators. In a pre-dawn raid more than 13 months after the attack, FBI agents and local police arrested Kyrgyzstan native Khairullozhon Matanov in Quincy for obstruction of justice, including lying to investigators and destroying evidence:

Matanov destroyed, altered and falsified records in a federal investigation, and made false statements in a federal investigation, the U.S. attorney’s office said. A legal resident of the U.S. originally from Kyrgyzstan, Matanov is not accused of participating in the bombings or knowing about them in advance. …

Matanov knew Tamerlan and Dzhokhar Tsarnaev, and in the days after the April 2013 bombings that killed three people and injured more than 260, Matanov realized the FBI would want to talk with him because he shared their “philosophical justification for violence,” federal prosecutors said.

He talked to the brothers on numerous occasions after the bombings, and even took them out to dinner the day of the explosions, they said.

“In the days following the bombings, Matanov continued to express support for the bombings, although later that week he said that maybe the bombings were wrong,” the indictment said.

He tried to contact the brothers after he saw media reports identifying them as the suspects, prosecutors said.

He’s not accused of knowing about the attack in advance, but that could change. The indictment states that Matanov wasn’t just interested in the Tsarnaevs’ jihad after the fact, NPR reports:

After entering the U.S., he met and befriended Tamerlan Tsarnaev, who was killed during an altercation with police four days after the bombing. Matanov also knew Dzhokhar Tsarnaev, who was captured following a massive manhunt and is currently awaiting trial.

“Matanov participated in a variety of activities, including discussing religious topics and hiking up a New Hampshire mountain in order to train, like and praise the ‘mujahideen,'” warriors who defend Islam, the indictment states.

Matanov tried to call both brothers in the hours and days following the Boston bombing on April 14, 2013, and saw Tamerlan in person at least twice, prosecutors say.

That combined with the attempted destruction of evidence makes suspicion of prior knowledge look at least reasonable. Last week, the Department of Justice argued in a motion defending their interrogation of Dzhokhar Tsarnaev that they had reason to believe that the pair had some sort of tradecraft assistance. They may only have evidence of after-the-fact obstruction now, but they’ll still be looking into more possibilities.

Early on, it didn’t appear clear what the arrest meant:

There may be more to the Tsarnaev story than just disaffected youth. Stay tuned.