General unhappiness for his life. but they still have no known motive. the gunman, now saturday easterfying shooting at this mall in columbia, maryland. darion marcus aguilar is the shooter. reporter: police still aren t talking about a possible motive. although they say the 19-year-old aguilar lived in the same college park, maryland, neighborhood as one of the victims, 21-year-old brianna benlolo. we have not been able to verify any type of relationship at this point between him and either of our victims. we can t establish that there is one. we have not been able to establish there is not one. that is an open question. reporter: surveillance videos, police say, revealed that aguilar arrived by taxi at this upper level mall entrance around 10:15 saturday morning. walking by a children s carousel and carrying a backpack with two homemade explosive devices. over the next hour, they say, he went downstairs and then back up into skate board shop zumiez where benlolo worked alongs