The only "proof" is the one video of an extremely conspicuous dude with an umbrella break a few windows. Some people are saying the guy was an undercover cop from St Paul, but the I doubt that as looking at the pictures of the two side by side, the shape of the officer's and the lone dude's face around the eyes didn't look to match to me (the dude had more of sunken in structure, the cop, while his eyes looked to be deep in the head, didn't have the same structure). That, and he stood out like a sore thumb; don't know the weather that day, but no one else was wearing a long jacket AND a hoodie AND a full face respirator (I wear those at work. They are not fun to wear for prolonged periods of time). The St Paul police claimed that they're not the same person, but that's about it. Since no one decided to pin the fucker down and make him stop, we'll never know if it's the cop or someone else.