Suspected Boston Marathon bomber Tamerlan Tsarnaev sent text messages to his mother as early as 2011 indicating he was willing to give his life for Islam, Fox News reports.

The revelation was reportedly made during a Capitol Hill briefing on Tuesday during which the FBI told lawmakers about the discovery.

Investigators believe Tsarnaev, who was killed several days after the April 15 Boston bombing in a shootout with police, became more radicalized in his Islamic views in recent years. He is thought to have recruited his 19-year-old brother to help carry out the deadly terrorist attack that killed three innocent people and wounded more than 180 more.

“Dzhokhar Tsarnaev was caught alive but wounded on Friday and charged with use of a weapon of mass destruction, for which he could get the death penalty,” Fox News reports.

In another stunning new development, U.S. officials on Wednesday said the name of the dead suspect, Tamerlan Tsarnaev, was added by the CIA to a terrorist database 18 months ago. The officials spoke to The Associated press on the condition of anonymity because they were not authorized to speak publicly about the ongoing case.

Fox News has more insight into the future prosecution of Dzhokhar Tsarnaev.

The Associated Press contributed to this report.