1-800-tbi-find. sick joke or serious threat? >> people in littleton, colorado on edge. yesterday marks the 12th anniversary of columbine. a manhunt is underway in that town. police searching for a suspect in an attempted mall bombing one mile from the high school. justin joseph a reporter joins us. i understand you brought along a person who is very important to this investigation? >> reporter: that's right. you will hear from him in a moment. authorities say they are receiving hundreds of tips. they can comment on what those are. they say the investigation is keeping them here in colorado. they are looking for the person seen in that video described as a person of interest. last seen in this hallway over my shoulder, before all of this happened. in that video you can see him holding a target bag authorities won't say what was in that bag. in that haulway video captures