Fox News reported this morning that some investigators are voicing concerns that they were not given enough time to question Dzhokhar under the “public safety exception” invoked by the Justice Department.

Two officials with knowledge of the FBI briefing on Capitol Hill said the FBI was against stopping the investigators’ questioning and was stunned that the judge, Justice Department prosecutors and public defenders showed up, feeling valuable intelligence may have been sacrificed as a result.

The FBI had been questioning Tsarnaev for 16 hours before the judge called a start to the court proceeding, officials familiar with the Capitol Hill briefing told Fox News. Moreover, the FBI informed lawmakers that the suspect had been providing valuable intelligence, but stopped talking once the magistrate judge read him his rights.

The exact timeline is unclear. A transcript of the court proceeding shows Bowler asking a doctor if Tsarnaev was “alert.”

“You can rouse him,” she says in the transcript.

“How are you feeling? Are you able to answer some questions?” the doctor asks Tsarnaev, who nods.

Although Bowler advised Tsarnaev, an ethnic Chechen and U.S. citizen, of his Miranda rights, it remains to be seen whether anything he told investigators before Bowler arrived can be admitted as evidence against him — or whether such interrogations would even be needed to convict him, given the amount of other evidence referenced in the criminal complaint signed by FBI Special Agent Daniel Genck.

Some Republican lawmakers have criticized the Obama administration for deciding against treating Tsarnaev as an enemy combatant, which would allow more time for interrogating him. The public safety exception to Miranda lasts only 48 hours.