Massachusetts Gov. Deval Patrick says surveillance video from the Boston Marathon attack shows the suspect putting his backpack down and moving away in time to avoid being injured by the blast of the bomb inside it.
Patrick says the video clearly puts 19-year-old Dzhokhar Tsarnaev at the scene of the attack. Tsarnaev is in serious condition at a Boston hospital after his capture Friday.
Patrick says the video is "pretty clear about his involvement and pretty chilling, frankly."
He says he hasn't viewed all the surveillance tapes but has been briefed by law enforcement about them.
Tsarnaev's older brother, Tamerlan, is also considered a suspect. He died in a gun battle with police earlier Friday.
Investigators have determined the bombs were fashioned from pressure cookers packed with explosives, nails and other shrapnel.