Boston Marathon Bombers Probably Had Terrorist Training, Court Documents Say

In an effort to keep the suspected Boston Marathon bomber's bedside confessions from being thrown out of the case, prosecutors said Wednesday that the FBI believed suspects Dzhokhar Tsarnaev and his brother were helped by a terrorist group at the time of their arrest. The sophistication of their homemade bombs, the use of "burner" mobile phones and the coordination of their attack all pointed to a possible Al-Qaeda connection, the prosecutors in the court document filed Wednesday.

According to court documents, the suspected brothers allegedly used Christmas light fuses and model car detonators to build the explosives, a complicated process that the prosecutors argue would have been very hard for the boys to learn on their own. "These relatively sophisticated devices would have been difficult for the Tsarnaevs to fabricate successfully without training or assistance from others," the U.S. Department of Justice said in Wednesday's court filing, according to NBC news.

The prosecutors also said that, in spite of the fact that Dzhokhar and Tamerlan Tsarnaev had allegedly used the powder from hundreds of fireworks as fuel for the explosives, no residue was found in their homes or cars — "strongly suggesting that others had built, or at least helped the Tsarnaevs build, the bombs, and thus might have built more [bombs]."On top of that, the fact that the brothers knew to use prepaid "burner" also suggests that they "had received training and direction from a terrorist group," the documents said.

The prosecutors are pushing hard to create a connection between the brothers and a terrorist group in order to make sure that Dzhokhar's confessions — which the feds got while he was in hospital, without reading him his Miranda rights and without giving him access to a lawyer — are kept in the case. If they can prove that there was a major threat to public safety, the statements can be used in court.

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"In light of the history of coordinated terrorist attacks such as the ones in Mumbai, India, Times Square, the New York subway system, and on September 11, the FBI had a duty to be investigate whether any additional attacks were imminent," Wednesday's court documents read. "Interviewing Tsarnaev as soon as possible was therefore essential to protect the public from possible harm."

Tsarnaev's attorneys have maintained that Tsarnaev’s interview was "obviously an effort to extract as much incriminating information as possible,” and should be inadmissible in court. Not only was he heavily medicated and denied access to an attorney, he couldn't even actually speak at the time because his jaw was wired shut — instead, he answered the FBI's questions in writing.

But the prosecutors argue that “they took steps to increase his comfort, such as removing his handcuff every time they entered the room, adjusting his pillows as needed, and summoning nurses for him at his request." They conclude: “There is simply no basis for finding on the facts of this case that the length of questioning was coercive."

Tsarnaev — who is accused of killing three people and injuring another 264 on April 15, 2013 in the worst bombing the U.S. has seen since 9/11 — faces 30 charges in court. The trial is set to start in November, and prosecutors will be seeking the death penalty.