Lawyers for accused Boston Marathon bomber Dzhokhar Tsarnaev asserted Friday that his older brother and alleged accomplice had been encouraged by the FBI to be an informant and to report on the Chechen and Muslim community, according to court records.

“We seek this information based on our belief that these contacts were among the precipitating events for Tamerlan’s actions during the week of April 15, 2013, and thus material to the defense case in mitigation,” the lawyers said in their court filing…

The lawyers suggested that Tamerlan Tsarnaev could have misinterpreted his interactions with the FBI as pressure from the agency, and that they could have “increased his paranoia and distress.”

The defense wants to investigate those factors as it seeks to portray Tamerlan as a dominating family figure who may have pushed the younger Dzhokhar to take part in the April 15 bombings last year. Tamerlan was killed days after the bombings in a confrontation with police in Watertown.