Transcript for Maryland Mall Terror
here to the latest on that deadly shooting in a suburban mall in Maryland. Tonight, we now know who the gunman is and we're learning chilling details of the attack. Roaming around inside the mall with his gun for more than an hour before he opened fire. ABC's Jeff Zeleny on the case again tonight. Reporter: On this suburban street near Washington, police say Darion Aguilar started his deadly plot. Dare Darion is a good kid. Don't know what happened. Reporter: 19 years old and out of high school less than a year, suddenly opening fire at a shopping mall in Columbia, Maryland. We spoke to his mother by phone today. She sobbed, telling ABC news her son "Never had any interest in guns." But tonight, police releasing new details of the attack. At 10:15 A.M. Saturday, he was dropped off by a taxi cab. For the next hour, he walked around the mall, his 12-gauge shotgun, bought only last month, somehow concealed. His backpack filled with crude explosive devices. At 11:15 A.M., calls to police came pouring in. We have report of an active shooter in the mall. Reporter: He fired six to eight shots, killing two employees at a skateboarding shop. One was 21-year-old Brianna benlolo, a young mother. The other, Tyler Johnson, 25. Authorities are still trying to unravel the connection between the gunman and his victims. And tonight, still so many questions about what led this young man to kill. But police telling us they've recovered a journal in his home, in which he writes about the unhappiness in his life.
This transcript has been automatically generated and may not be 100% accurate.