Boston marathon bombing suspect Dzhokhar Tsarnaev suffered multiple and severe gunshot injuries before his capture in April, newly released court documents show.

The most serious of the injuries was a gunshot wound that appeared to enter through the left inside of his mouth and exit through the lower left side of his face, said Stephen Ray Odom, a trauma surgeon who treated Tsarnaev at Beth Israel Deaconess Medical Center.

"This was a high-powered injury that has resulted in skull-base fracture, with injuries to the middle ear, the skull base, ... his ... vertebrae ... as well as injury to the pharynx, (and) the mouth." Odom said in testimony given April 22, three days after Tsarnaev was arrested following the bombing.