The Boston bombing suspect captured alive Friday night suffered an injury to his throat and may not be able to talk, a federal official said this weekend.
Officials also believe that Dzhokhar Tsarnaev and his deceased brother were hoping to launch more violent attacks before they were caught last week.
This is likely, given the large quantity of explosives and ammunition they possessed, yet all evidence suggests the two brothers were acting alone.
"All of the information I have is they acted alone, these two individuals, the brothers,'' Boston Mayor Thomas M. Menino said on ABC's This Week.'
"The older brother's dead now. We have the second one ... in very serious condition,'' he said. "We don't know if we'll ever be able to question the individual."
Menino's comment only fueled more questions about the medical condition of Dzhokar Tsarnaev, whose injuries have not been disclosed - officially.
The official, who was briefed on Tsarnaev's condition and reported the throat injury, spoke on condition of anonymity. It's clear Tsarnaev hasn't spoken at all - yet.
Federal prosecutors continue to patrol the heavily guarded Beth Israel Deaconess Medical Center, where Tsarnaev is being treated for his wounds.
Authorities have not publicly detailed the injuries sustained by the teen, but another official said Sunday that he has been "intubated and sedated."
The official also spoke on condition of anonymity.
A Justice Department official said that the 19-year-old will likely face federal terrorism charges and possibly state murder charges, no matter what.
The government has invoked the public safety exception, a designation that allows investigators to question the teen without reading him his Miranda rights.
Tsarnaev, 19, and his older brother, Tamerlan Tsarnaev, 26, are accused of setting off two bombs near the finish line of the Boston Marathon on Monday.
Three people died and more than 170 were injured.
The most serious charge available to federal prosecutors would be the use of a weapon of mass destruction, which carries a possible death sentence.
Massachusetts does not have the death penalty.
U.S. officials said an elite interrogation team would question the Massachusetts college student, assuming that's even an option. At this point, it's unclear.
