The surviving Boston bomber suspect scrawled a note inside the hull of the boat in which he hid that said the attack was carried out in retaliation for the actions of the United States against Muslims, sources confirmed to NBC News.
The information was first reported by CBS, which described the note as scrawled with a pen on the interior wall of the boat's cabin.
The only living suspect of the April 15 Boston Marathon bombing, Dzhokhar Tsarnaev, repeated many of the points from the note when he explained his motives to law enforcement investigators who interviewed him from his hospital bed. He referenced the U.S. wars in Afghanistan and Iraq.
The 19-year-old hid in a boat in the Boston suburb of Watertown as police pursued him days after he and his older brother Tamerlan allegedly planted homemade bombs near the finish line of the Boston Marathon.
Earlier this month, the director of the Worcester, Mass., funeral home where Tamerlan Tsarnaev's body was kept said that cemeteries across Massachusetts refused to bury him. Tamerlan, who was killed during the pursuit, was ultimately buried in a small Muslim cemetery in Doswell, Va., a community about 15 miles from the state capital, Richmond.
Tsarnaev told his interrogators the weekend after he was arrested that he and his brother originally intended to set off their bombs somewhere on the Fourth of July.
The older Tsarnaev left behind a wife, Katherine Russell Tsarnaev, and a 3-year-old daughter. Law enforcement officials are still investigating Russell's involvement in the incident.
Reporting contributed by NBC's Richard Esposito.