We are learning more this morning about the chilling massacre plot at the university of central florida. The alleged aing thatter reportedly ordering $700 worth of weapons online. Police revealing... See More
We are learning more this morning about the chilling massacre plot at the university of central florida. The alleged aing thatter reportedly ordering $700 worth of weapons online. Police revealing that he left behind a terrifying to do list where he outlined the damage he was planning. Abc's matt gutman is in orlando with the very latest on this. Matt, good morning. Reporter: Good morning, amy. That's right. We know he would meticulously check items off pulling the fire alarm to try to get hundreds of students in here and begin shooting. Police don't know why I didn't follow through but do know he had an arsenal prepared. This morning, the heart-pounding video. Stumbling across what they say was a failed massacre at the university of central florida. You're seeing video shot through body-mounted cameras. Police bursting into james oliver seevakumaran's room, the pistol, the automatic rifle, bombs in the backpack and we're learning how much worse it might have been. Police say seevakumaran sent himself packages. This he arrived tuesday morning after his death. What was in the mail waiting for the deceased were two .22 round magazines, a black hawk tactical sling and there was also a training dvd. Reporter: But most explosive perhaps this check list. Ending with two items, fire alarm and give them hell. The suspected shooter pulled this fire alarm, down, went back into his unit here then ep drabbed his gun. Police arrived with the help of this 911 call. My roommate just pulled a fire alarm and he's got a gun out. Reporter: The roommake aruba babakhani. And he slammed the door. Police say babakhani helped prevent a massacre. Now, 100,000 students go to the school and this morning there's still questions. Were there any warning signs and how did the student manage to smuggle in so many weapons into a dorm room? Amy? So many questions, matt gutman, thanks so much.
This transcript has been automatically generated and may not be 100% accurate.