The mother of the remaining suspect in the Boston Marathon bombings says her son has recovered enough to walk.

(Photo provided by FBI via Getty Images)

Zubeidat Tsarnaev tells The Associated Press that 19-year-old Dzhokhar Tsarnaev walked without a wheelchair to speak to his mother last week for the first and only phone conversation they have had since he has been in custody.

She says he assured his parents that he and his slain brother are innocent of the April 15 bombings that killed three people and wounded more than 260.

Zubeidat Tsarnaev says her son told her he's getting better and has a very good doctor, but he's struggling to understand what happened. She says she could feel that he's "being driven crazy by the unfairness" of the situation and the death of his brother, Tamerlan, in a shootout with police.

The suspects' father says he still hoping that his sons will be cleared, and Dzhokar will return to their home "crippled, but at least alive."

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