Tragedy in Colorado: Movie Theater Massacre Sunil Tripathi: New Video in Missing Ivy League Student Case Officials continue to look for clues of the young man who vanished without a trace. Teen Denies He's the Marathon Bomber Salah Barhoun, 17, had his name cleared by police after his face appeared on TV, social media. Boston Marathon: What Was the Bomb? Officials recover part of a "pressure cooker" IED. Identifying the Boston Marathon Bomber Special FBI team works digital clues from thousands of images. FBI Hunts 2 Suspects in Marathon Bombing Feds enlist public to help catch Suspect 1 and Suspect 2. Texas Explosion Registered on Richter Scale Casualties at a fertilizer-plant explosion are estimated to be between 5 and 15. Photos of Boston Bombing Show Man Running It's unclear if the man in pictures taken right after the bomb went off is just in panic or not. The Hunt for the Boston Marathon Bomber Former counterterrorism head Dick Clarke discusses the marathon bombing investigation. Boston Marathon Bombings: FBI Releases Images of Suspects Authorities seek public's help in identifying two men seen in surveillance footage. Missing Missouri Mom Faked Abduction, Sheriff Says Authorities believe Rachel Koechner, 28, was in a motel and using drugs with her ex-husband. Woman Sues CVS Over Alleged Racist Receipt Hyun Lee claims an employee at a N.J. CVS referred to her on a receipt as "Ching Chong Lee." 'Significant Devastation' in West, Texas, Explosion Waco Police Sgt. William Patrick Swanton talks to "GMA" about rescue efforts and aftermath. Colorado Police Want to Talk to Missing Woman's Roommate Leann "Annie" Meyer, 52, has been missing for nearly two weeks. Marathon Photographer Captures Images of Horror Boston Globe's John Tlumacki on photographing the chaos at the finish line. Texas Town Devastated by Blast at Fertilizer Plant Tragedy outside Waco, Texas, following mysterious blast involving dangerous chemicals.