I know the area well. I used to work in one of the buildings in the area and there are tons of places you could have a vehicle parked ready to go. Just drive two blocks and you can be on I-35 in less than a minute. One block over and there's a Greyhound Bus Station you could hop on and be gone in no time. It's also close to the Earl Cabell Federal Building.
My guess is this is another one of George Soro's staged activist schemes and that the shooting was pre-planned. I expect the suspects involved will be shot and killed to cover tracks.
10 shot, now 3 are dead
2 Snipers shot from several elevated areas, 2 or so officers critical
No suspects in custody