The Boston marathon bomb investigation is focusing on some people seen videos taken just before the Monday blasts.
FOX News Radio's Rich Johnson reports from Washington:
They are not suspects, but there are some people who appear on videos the FBI would like to talk to.
(Napolitano) "We need the public's help in locating these individuals."
Homeland Security Secretary Janet Napolitano also tells the House Homeland Security Committee, don't expect instant results, as if you're watching a TV show.
(Napolitano) "This is not an NCIS episode. Sometimes you have to take time to properly, you know, put the chain together."
Napolitano also says it's not yet clear whether the Boston marathon bombs were the work of foreign or domestic terrorists.
In Washington, Rich Johnson, FOX News Radio.
Around the blast sites and beyond, the search continues for any clues that could help the investigation.
FOX News Radio's Jeff Monosso reports from Boston:
Makeshift memorials filled with flowers and notes continue to grow here near the blast zone. The FBI also continues working around the clock to find those responsible, chasing down several different leads and tracking down people who were seen on surveillance video near where the bombs blew up.
We're told investigators are weighing the advantages of releasing those images to the public in hopes someone might recognize a potential suspect. But we also know the FBI does not want to do anything that might jeopardize their case.
In Boston, Jeff Monosso, FOX News Radio.
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