The surviving suspect in the Boston Marathon bombings has a throat injury and may not be able to talk, a federal official has told CNN.

That could severely inhibit the ability of authorities to interrogate Dzhokar Tsarnaev, who was captured Friday night after a shootout that followed a massive manhunt.

With one suspect dead, authorities believe answers to a motive and whether the brothers had help rest with Dzhokhar Tsarnaev. The 19-year-old ethnic Chechen, whose older brother, Tamerlan Tsamaev, was killed in a shootout Thursday, is in serious condition at a Boston hospital.

Tsarnaev has not been charged yet, but CNN reported that charges could be filed Sunday. However, Justice Department officials said late in the day, that charges would not be announced until Monday at the earliest. They did not give a reason for the delay.

Federal prosecutors are at the heavily guarded Beth Israel Deaconess Medical Center, where Dzhokhar Tsarnaev is being treated for wounds. Authorities have not publicly detailed the injuries sustained by the teen.

“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," Massachusetts Gov. Deval Patrick said at a news conference Saturday. There are parts of the investigation, in terms of information and evidence, that still needs to be run to ground."

Authorities have not said whether they have questioned Tsarnaev, nor have they publicly said what charges will be filed against the teen. But a Justice Department official, speaking on condition of anonymity, told CNN the teen will face federal terrorism charges and possibly state murder charges.

The government has invoked the public safety exception, a designation that allows investigators to question the teen without ading him his Miranda rights and without a lawyer present, another Justice Department official, also speaking on condition of anonymity, told CNN.

Charges coming at any moment

Because Tsarnaev is still in serious condition, a judge would come to his hospital bedside to charge him, a law enforcement source told CNN, noting that suspects who face federal charges are normally arraigned within 48 hours of arrest. Tsarnaev is currently unable to speak.

Authorities have not said publicly what charges will be filed. A Justice Department official, speaking on condition of anonymity, told CNN he will face federal terrorism charges and possibly state murder charges.

Although Massachusetts does not have the death penalty, prosecutors could seek the death penalty at the federal level, the Justice Department official said.