Seventeen-year-old Trayvon Martin was killed by a single gunshot to the chest at an “immediate range,” autopsy reports show. The latest findings are igniting further speculation on what exactly happened the night that George Zimmerman shot the unarmed teen within a gated Florida community in February.

NBC News first reviewed the autopsy report on Wednesday, unearthing new documents to be released, including a witness statement and a surveillance video, details that Martin’s family says they have yet to receive.

One finding showed that Martin had an “abrasion on his left ring finger below the knuckle,” NBC’s National Correspondent Michael Isikoff told MSNBC’s Thomas Roberts.

“The bruised knuckle on Trayvon Martin’s fist and the injuries to George Zimmerman could be consistent and be helpful to Zimmerman's defense that he only shot Trayvon Martin after a struggle that had been violent," Isikoff said.

Zimmerman, 28, was charged with second-degree murder last month, after he claimed self defense under Florida's controversial "Stand You Ground" law. He was released on a $150,000 bond.

A recent medical report showed that a family physician found a “closed fracture” on his nose, two black eyes, with two additional “lacerations to the back of his head and a minor back injury” from his confrontation with Martin.