Massachusetts Gov. Deval Patrick says the decision to lock down much of greater Boston during the search for the surviving suspect in the marathon bombing was a ``tough call'' but one he's glad was made.

Patrick reflected on the April 19, 2013, shelter-in-place request during a recent interview about the anniversary of the attack.

Hours after an early morning shootout with police in Watertown that left one suspect dead, Patrick shut down the region's public transportation system and asked more than a million people in the metropolitan area to shelter in place. Most everyone did.

Patrick concluded that the suspect was extremely dangerous.

Dzhokhar Tsarnaev was captured that evening in a boat behind a Watertown home, shortly after the lockdown was lifted.  (Associated Press)