Boston bombing was payback for hits on Muslims

Susan Candiotti, CNN.

(CNN) -- Boston Marathon bombing victims were collateral damage in a strike meant as payback for U.S. wars in Muslim lands, the surviving suspect wrote in a message scribbled on the boat where he was found hiding, a law enforcement source told CNN Thursday.

In the message, Dzhokhar Tsarnaev also proclaimed that an attack on one Muslim is an attack on all, and said he would not miss older brother Tamerlan Tsarnaev -- who died after a firefight with police three days after the bombing -- because he would soon be joining him, according to the source.

The writing on the inside of the boat dovetails with what Dzhokhar, 19, told investigators questioning him in a Boston hospital room shortly after his capture, the source said.

CNN has previously cited U.S. officials in reporting that Dzhokhar said U.S. involvement in Afghanistan and Iraq were motivating factors behind the April 15 attack, which killed three people and wounded 275.

According to authorities, the Tsarnaev brothers fashioned explosive devices from pressure cookers and other materials and detonated them near the finish line of the race.

Three days later, authorities released their images to the public as suspects in the case. Investigators believe they then killed MIT police Officer Sean Collier and hijacked a car before battling authorities in a wild firefight on a Watertown, Massachusetts, street.

Nearly 24 hours later, police found Dzhokhar hiding in the boat after the owner called police to report someone was inside of it.

The final hours that paralyzed Boston

Dzhokhar -- who suffered gunshot wounds to the head, neck, legs and hands -- is being held a federal Bureau of Prisons medical facility in Devens, Massachusetts. He has been charged with using a weapon of mass destruction and could face the death penalty if convicted.

Tamerlan was secretly buried in a rural Virginia cemetery this month following protests from Massachusetts residents and officials against burying him in that state.

Authorities have said they believe the brothers acted alone, but are investigating whether they could have learned from or been aided by terror groups, including groups overseas.

Of particular interest has been Tamerlan's 2012 trip to the semi-autonomous Russian republic of Dagestan, home to numerous Islamic militant groups that have warred against Moscow's rule.

Read More: http://edition.cnn.com/2013/05/16/us/boston-bombing-investigation/index.html