Police capture second Boston marathon suspect

It started just as it was getting dark on Friday -- armored vehicles and police with assault weapons moved in on Boston Marathon suspect Dzhokhar Tsarnaev. Media are reporting that the 19-year-old is a live and now in police custody

Many in the Boston suburb of Watertown reported hearing gun shots as the operation began.

Police will now focus on interrogating him about the explosion and possible links to violent groups.

This image released by FBI earlier in the day shows him purchasing Red Bull energy drinks at a local convenience store ahead of the shootout that killed his brother.