When Tsarnaev was pulled from a boat stored in a Watertown backyard Friday night, ending five days of fear, the 19-year-old bombing suspect was disoriented and weak from loss of blood.
The extent of Tsarnaev's wounds, likely sustained during the firefight Thursday night with law enforcement that killed his older brother, has not been officially released to the public.
But an official told CBS News Tsarnaev may have tried to commit suicide.
"They say it appears from the wound that he might have stuck a gun in his mouth and fired, and actually just went out the back of his neck without killing him," explained CBS correspondent John Miller, a former FBI spokesman.
"That's one of the reasons he's unable to communicate," Miller said. "But he can understand what they're saying and they believe there's going to be a point where he'll be able to talk to him."
Tsarnaev has also been intubated and sedated.
"I, and I think all of the law enforcement professionals, are hoping for a host of reasons that the suspect survives, because we have a million questions, and those questions need to be answered," said Massachusetts Gov. Deval Patrick Saturday, telling reporters Tsarnaev is in "serious but stable condition".
In addition to the neck wounds, Tsarnaev also suffered gunshots to the leg.
Federal prosecutors are preparing to charge Tsarnaev, likely with federal terrorism charges and possibly state murder charges, expected to be filed later Sunday.