Update, Monday: There are now federal charges, delivered to Dzhokhar Tsarnaev as an American citizen, in his hospital bed (reportedly along with his Miranda warning), and they involve pressure cookers as WMDs, even as questions surround the investigation and his family. Read the full transcript of the hearing below:

Update, 8:34 p.m.: Sources tell ABC News and NBC News that Dzhokhar Tsarnaev regained consciousness and began answering written questions from police on Sunday night. The 19-year-old is still in serious condition but is reportedly fielding questions about other potential members of a terrorist cell and unexploded bombs that might still be out there. It remains unclear if Tsarnaev will ever be able to talk again after taking a gunshot wound to the throat.

Meanwhile, more details about Dzhokhar and his brother Tamerlan continue to emerge. The Los Angeles Times managed to track down the brothers' mother, Zubeidat Tsarnaev, who characterized her last conversation with the older, now late Tamerlan just hours before his shootout with police last Thursday night. "He would call me every day from America in the last days," she told The Times from her home in Dagestan, "and during our last conversation on the morning [before the shootout], he was especially touching and tender and alarmed at the same time. He said he got a private phone call from [the FBI] and said that they told him he was under suspicion and should come see them." Just before hanging up, he added, "If you need me, you will find me."

Zubeidat suggested that American authorities have had their eye on Tamerlan for a while — or at least, he thought they did. "You know the FBI followed him for several years," she said, "and when he got back from Dagestan last year they called him and asked him what was the purpose of his visit to his homeland."

Original Post: Dzhokhar Tsarnaev is still in the hospital. His condition is not improving, and he still can't speak to investigators because of a potentially self-inflicted neck wound. The 19-year-old suspect is still under surveillance at Beth Israel Deaconess Medical Center, where he's been since his arrest late Friday night. He was in serious but stable condition Sunday morning, according to the F.B.I., but the Boston Police Department just released an update saying it's been downgraded to critical but stable condition. That's bad. That means his condition is getting worse. 

The truth is, there's a very real possibility investigators won't get a chance to speak with Dzhokhar Tsarnaev. "We don’t know if we’ll ever be able to question the individual," Mayor Tom Menino cautioned Sunday morning on ABC's This Week.

What's holding them up and causing the most serious problems is a neck wound that's hampering his ability to speak with the special interrogators brought in for when he is eventually healthy enough to explain himself. The New York Times reports Tsarnaev has a breathing tube down his throat and he's currently sedated because of what appears to be a self-inflicted gunshot wound. The wound "had the appearance of a close range, self-inflicted style," a law enforcement source told the Times. This implies that Tsarnaev intended to kill himself before being taken alive, which doesn't bode well for hopes he might cooperate. Neither does the fact that he was "swearing profusely" during his initial ambulance ride before the neck wound silenced him, according to the L.A. Times

So the public should maybe start to prepare itself for what seems inevitable at this point: we may never hear an explanation for these attacks from the source. The Justice Department was expected to file charges against Tsarnaev on Sunday, but they decided to delay that decision, NBC's Pete Williams reports. All we can do is wait.