This is horrible.
Also, a general suggestion to everyone: don't immediately play politics with something like this. We don't know anything about the shooter. He might be a leftist, or he might be an anarchist. For all we know, he's a Trump voter. But no matter what he is, it doesn't matter--this is wrong.
Any infos about the motives of the terrorist?
Apparently he asked if they were Reps or Dems before he shot, so apparently anti-Republican. Don't know if this claim is valid but it is being reported. Maybe he was leftist or anarchist, possibly a disgruntled vet if he was a middle aged guy with weapons training but that is just suspect profiling on my part. Will update if I hear more.
Even though we don't know the motive, people on the left preemptively making the disingenuous argument that anarchists aren't leftists.