Police identified the two killed as Brianna Benlolo, 21, of College Park, Md. and Tyler Johnson, 25, of Ellicott City, Md. Both were employees of Zumiez, a store on the upper level of the mall that caters to young shoppers, police said at an afternoon press conference.
Law enforcement sources told NBCNews that the shooting appears to have begun with a domestic dispute. However, Howard County Police have not confirmed that report, saying the motive remains unknown and they do not know the identity of the shooter.