(CBS News) Boston may never "be quite the same" in the wake of twin bombings last week that marked the first terrorist attack on American soil since 9/11, Massachusetts Gov. Deval Patrick said Sunday on "Face the Nation." But with the second suspect in custody as of Friday night, he added, the United States can breathe a sigh of relief.
"People are moving out and moving back into their regular routines, but vigilance is still the order of the day - and of course we're still trying to heal from a shocking tragedy less than a week away," Patrick said of two explosions Monday near the Boston Marathon finish line that killed three and left more than 100 gravely wounded.
"There's still an ongoing investigation," he continued. "There are lots of questions about how and why and so forth and many, many leads still to be tracked down. But the immediate threat, I think all of law enforcement feels, is over, based on the information we have. And that is a good thin,g and you can feel the relief at home here."
Patrick on Friday advised a lockdown of the Boston area, before 19-year-old Dzhokhar Tsarnaev was found seriously injured, hiding in a tarp-covered boat in Watertown, Mass. His older brother and suspected accomplice Tamerlan died in a gun battle with police the night before.
There are always "kunckleheads" who chose not to heed the lock down advisory, Patrick said, but added that overall the cooperation of the public was "part of this investigation in many, many respects, and their having responded to requests to submit photographs, and videotapes, and so on." Federal investigators on Thursday released surveillance video of the Tsarnaev brothers at the Boston Marathon in a public plea to help identify the suspects.
Earlier on the program, Boston Police Commissioner Ed Davis said an elite interrogation team will question the 19-year-old college student without reading him his Miranda rights - something allowed only on a limited basis when the public may be in immediate danger. The suspect remains now in "serious but stable condition."
Davis said "at least four" unexploded devices were found at the scene, similar to the improvised homemade explosives made with materials like pressure cookers and shrapnel used in the Marathon bombings. "Based upon the evidence that was found at the scene," Davis continued, the two suspects were planning additional attacks.
No answers yet exist as to the pair's motive, Patrick said.
"It's hard for me and for many of us to imagine what could motivate people to harm innocent men, women and children in the way that these two fellows did," he said.
House Homeland Security chairman Michael McCaul, R-Texas, said in an appearance later on the show that moving forward his investigation will focus on details about when the elder suspect - of Chechen roots, along with his brother - became entrenched in radical philosophy.
"My theory is, he was radicalized by 2009, 2010," McCaul said. "You have to look at where they came from right, the father, the family. We have to understand Chechnya, the Chechen rebels, some of the fiercest Taliban or jihadist fighters out there having an allegiance with al Qaeda in Pakistan and Afghanistan. So when you look in that world historical context, it starts to make a little more sense, of putting the pieces of the puzzle together."