Eventually police got a clearer look at both suspects - brothers Tamerlan and Dzhokhar Tsarnaev. And, through Tamerlan's YouTube page, discovered his support of jihad or Islamic holy war.

In the end, it was not a printed news release, phone calls or a news conference that announced the capture of Dzhokhar Tsarnaev. It was a twitter message posted by the Boston Police Department.

It said "Captured! The search is done. The terror is over. And justice has won."

VOA found out through a police two-way radio on the scene in Watertown. Boston's mayor sat in a police cruiser, grabbed the radio and addressed the officers saying, "We got him! Congratulations and Thank you".

Sean Mussenden teaches digital journalism at the University of Maryland. He says this is the new normal for investigations.

"It’s also the present, the modern media landscape in which we live. The audience is a huge active participant in these sorts of stories," he said.

From surveillance cameras to cellphones to facebook to twitter to YouTube - the Boston bombing investigation relied on it all. But in the end, it was the public and their social connections that helped police crack the suspects' identities.