Boston Marathon bombing investigation turns to motive

Tsarnaev had been hiding in a boat parked in the backyard of a house in the suburb of Watertown, police said. A resident called police after spotting blood on the boat. Police said he was bleeding and in serious condition when admitted to the hospital.  This image, obtained courtesy CBS News, shows Dzhokhar Tsarnaev, a suspect in the Boston Marathon bombing who was captured Friday night after he was found hiding in a boat in a Boston suburb.

Reuters/Boston

 With the surviving suspect in the Boston Marathon bombings lying seriously wounded in a hospital, investigators worked yesterday to determine a motive and whether the ethnic Chechen brothers accused in the attack acted alone.

Dzhokhar Tsarnaev, 19, was captured late on Friday after a gunfight with police that ended a daylong manhunt and sent waves of relief and jubilation throughout Boston. His brother Tamerlan, 26, was killed on Thursday in a shootout with police.

Tsarnaev was being treated at Beth Israel Deaconess Medical Center in Boston, said an official.  It was not clear when he would be charged.

The brothers are suspected of setting off bombs made in pressure cookers and packed with ball bearings and nails at the crowded finish line of the marathon, killing three people and injuring 176.

After Monday’s deadly bombings and the manhunt that shut down the Boston metropolitan area for most of Friday, life yesterday regained some sense of normalcy.

Boston’s Red Sox baseball team returned to Fenway Park for the first time since the bombings, paying an emotional tribute to the victims and the first responders before the game against the Kansas City Royals.