FBI release chilling video of Boston bomber placing explosives next to kids watching marathon​

The FBI released surveillance video that shows the Tsarnaev brothers in the moments before the bombs went off at the 2013 Boston Marathon. The video shows Tsarnaev walking with his brother, Tamerlan, each carrying a backpack. Dzhokhar Tsarnaev dips his shoulder and puts the backpack with the bomb at his feet. When all heads turn and look toward the sound of an explosion. Dzhokhar doesn't look and begins walking in the opposite direction. Three people died and more than 260 were injured when two pressure-cooker bombs filled with shrapnel exploded near the finish line at the Boston Marathon.