Did the Tsarnaev brothers have help making the Boston Marathon bombs?

Dzhokhar Tsarnaev told police he and his brother built the bombs, but court documents show some people involved in the case had their doubts.

The bombs were described as powerful pressure-cooker explosives controlled remotely. There were fuses from Christmas lights and detonators constructed from model car parts.

The twin bombings in April 2013 killed three people and wounded more than 250 others.

“These relatively sophisticated devices would have been difficult for the Tsarnaevs to fabricate successfully without training or assistance from others,” prosecutors wrote in a filing opposing a move by Tsarnaev’s lawyer to throw out statements he made in the hospital.