Massachusetts Gov. Deval Patrick said Saturday afternoon that Tsarnaev was in serious but stable condition and was probably unable to communicate. Tsarnaev was at Boston's Beth Israel Deaconess Medical Center, where 11 victims of the bombing were still being treated.
"I, and I think all of the law enforcement officials, are hoping for a host of reasons the suspect survives," the governor said after a ceremony at Fenway Park to honor the victims and survivors of the attack. "We have a million questions, and those questions need to be answered."
The all-day manhunt Friday brought the Boston area to a near standstill and put people on edge across the metropolitan area.
The break came around nightfall when a homeowner in Watertown saw blood on his boat, pulled back the tarp and saw a bloody Dzhokhar Tsarnaev hiding inside, police said. After an exchange of gunfire, he was seized and taken away in an ambulance.
Raucous celebrations erupted in and around Boston, with chants of "USA! USA!" Residents flooded the streets in relief four days after the twin explosions ripped through the marathon crowd at the finish line, killing three people and wounding more than 180.
Michael Spellman said he bought tickets to Saturday's Red Sox game at Fenway Park to help send a message to the bombers.
"They're not going to stop us from doing things we love to do," he said, sitting a few rows behind home plate. "We're not going to live in fear."
During the long night of violence leading up to the capture, the Tsarnaev brothers killed an MIT police officer, severely wounded another lawman and took part in a furious shootout and car chase in which they hurled explosives at police from a large homemade arsenal, authorities said.