The widow of one of the Boston bombers sent a revealing text after the tragedy

The widow of a man who has been accused of bombing the Boston Marathon in 2013 brought up the conflict in Syria in a text she sent to a friend after the attack.

Katherine Russell, who converted to Islam after entering into a relationship with accused terrorist Tamerlan Tsarnaev, reportedly texted a friend shortly after the bombs went off: "As far as I know Tamerlan was at home in Cambridge."

She added later: "Although a lot more people are killed every day in Syria + other places. Innocent people," according to The Daily Beast and Boston.com.

The text was revealed in court as part of the sentencing phase of Dzhokhar Tsarnaev's trial. His defense attorneys are arguing that his older brother, Tamerlan, was the driving force behind the attack and influenced Dzhokhar to participate. Tamerlan died during the manhunt for him and Dzhokhar the week of the bombing.

Investigators are looking into how much Russell knew and when. Some bomb components were found at the home Russell shared with Tamerlan, but Dzhokhar said after police apprehended him that she wasn't part of the attack.

But it's clear that Tamerlan influenced Russell's views significantly. Friends and her mother told the court that Tamerlan urged her to convert to Islam and she came to embrace it.

And the search history on Russell's laptop is pretty damning.

BuzzFeed News reporter Mike Hayes, tweeting from the trial, reports that a laptop registered to Russell shows searches for: "if your husband becomes a shahid [martyr] what are the rewards for you?" and "rewards for wife of mujahideen [Islamic fighter]" from 2012.

Radical interpretations of Islam were clearly a motivating factor in the brothers' attack.

A bloodstained message that Dzhokhar wrote insider a boat he hid in while police were searching for him read: "We Muslims are one body you hurt one you hurt us all," citing what it said was aggression in Muslim lands.

"I don't like killing innocent people it is forbidden in islam, but due to said (…) it is allowed," the message read, according to Reuters.

A jury will soon decide if Dzhokhar will be sentenced to death for the attack that killed three people and injured more than 200 others near the finish line of the Boston Marathon. He has been found guilty for the crimes.