President Obama says explosions at the Boston Marathon are being investigated as an act of terror. He called the bombing "a heinous and cowardly act" used to target innocent civilians. Three people were killed and more than 170 were wounded.
A person briefed on the investigation says the explosives contained shards of metal, nails, and ball bearings. They were loaded into six-liter pressure cookers, placed inside black duffel bags, and set on the ground.
Luke Bencie, president of Security Management International, discussed the implications of Monday's bombing with Capital Insider.