Former FBI Special Agent in Charge of the Buffalo office Bernie Tolbert watched the standoff unfold and lead to an arrest last night.
He said the bureau's work has only just begun.
There is still a mountain of evidence to collect from multiple crime scenes.
The suspect still needs to be interviewed and keep in mind there are dozens of victims, some in critical condition who likely haven't been interviewed yet.
Tolbert and another former special agent told 2 On Your Side capturing the Dzhokhar Tsarnaev was the best possible outcome because there were no further incidents and because they hope to learn more from him about a motive and potential accomplices.
Meantime, Tolbert is reminding people to be vigilant and if you see something, say something.
"A good lesson for the public is if you see something under any circumstances that just doesn't look right that you think there's something wrong, I think that's important to bring that to the attention of whomever the proper authorities are because as much as we in law enforcement like to think we're good and we are good, then often, more often than not, it's somebody in the public telling you something that puts you on the right track."
The owner of a boat noticed a strap holding down the cover had been cut and he saw what he believed to be blood on the cover so he notified police.
That boat is where police found Tsarnaev.