 Investigators are going to be looking at whether this individual acted alone or was working with others. They'll look at the gun, how and where it was obtained. And, of course, they'll be looking for a potential motive. At a press conference around midnight last night, FBI Special Agent Kevin Rojek said investigators had not identified a motive yet. Investigators will be digging through the suspect's social media for that, phone records, computer web search history. They'll talk to people who the suspected shooter was in contact with in recent days and weeks.