I see the question as one of either a forced martial law ordering people to stay home, or a reasoned request for people to stay off the streets to help aid in the manhunt.
Let's start with the latter.
The people of Boston took great pride in their annual marathon. As a society, they would naturally want to do whatever they could to help the city and state to capture the criminals. By asking people to stay off the streets, then anyone who is out on the streets would stand out and attract suspicion. As long as the stay request doesn't drag on forever, most people would support this as a short-term effort to smoke out the bombers.
Regarding the former, a city-wide curfew order that criminalized being found on the street would not sit well for most citizens. A governor might get away with it once in an extreme situation (like the marathon bombing), but it can't become a go-to tool for anything the governor wants. People won't accept being under effective house-arrest because a kidnapper is on the loose, or a bank was robbed or building burned.
-PJ
>> People won’t accept being under effective house-arrest because a kidnapper is on the loose, or a bank was robbed or building burned.<<
But they WILL let a freeway get shut down for 12 hours if there is a fatal accident.