Boston police Commissioner Ed Davis (at podium), accompanied by Massachusetts State Police Col. Timothy Alben (second from right) and Gov. Deval Patrick (right), speaks during a news conference after the arrest of 19-year-old Dzhokhar Tsarnaev, a suspect of the Boston Marathon bombings, in Watertown, Mass., on Friday, April 19, 2013. (AP Photo/Matt Rourke)

Photo by: Matt Rourke

Boston police Commissioner Ed Davis (at podium), accompanied by Massachusetts State Police Col. Timothy Alben (second from right) and Gov. Deval Patrick (right), speaks during a news conference after the arrest of 19-year-old Dzhokhar Tsarnaev, a suspect of the Boston Marathon bombings, in Watertown, Mass., on Friday, April 19, 2013. (AP Photo/Matt Rourke)