Threat assessment, preparation can help prevent college shooting deaths, experts say

Reporters copy photographs of three of the victims of the mass shooting at Umpqua Community College that were displayed at a news conference, Friday, Oct. 2, 2015, in Roseburg, Ore. In the photos, from left, are Quinn Cooper, 18, Lucas Eibel,18, center, and Jason Johnson, 33. They were among those killed when Chris Harper Mercer walked into a class at the community college the day before and opened fire. (AP Photo/Rich Pedroncelli)