It would seem he's not dressed/prepared for a long trip. Did he get home (next door) to equip himself before the SWAT team cleared it?
"Authorities released a photo of the suspect said to be taken as he fled after the shooting: Gaunt, barefoot and wearing nothing but black shorts, he is seeing walking down what appears to be a flight of outdoor concrete steps..."
"...[bar owner] Gwerder told The Associated Press... “He knew everybody that was in that bar. I guarantee you that,” ... ...He didn’t have any running dispute with any of them. I just think he snapped.”
"...Brown’s niece, Clare Boyle, told AP her uncle has struggled with mental illness for years and she and other family members repeatedly sought help.
“This isn’t just a drunk/high man going wild,” she said in a Facebook message. “It’s a sick man who doesn’t know who he is sometimes and frequently doesn’t know where or when he is either.”..