It was so just it was "injust"?
He did not impede an arrest. He was standing in the middle of the street directing traffic. He follows the federal agent's instructions and moves over to the sidewalk where he then films the agent and argues with him. Another agent comes over an pushes a woman to the ground for no reason. Pretti tries to step between the agent and the woman who was just violently shoved to the ground. The agent then starts spraying Pretti with pepper spray. Pretti raises his hand to block the spray and starts moving back away from the agent. The agent follows him in order to try and reach around his head to continue to spray him directly in the face even though Pretti is retreating.
Then he tries to help the woman up and is swarmed by multiple agents and put on the ground. The woman he tries to help up then gets pepper sprayed at point blank range in the face for no reason. She is attended to by another protestor as she appears to be in pain and having trouble breathing. Pretti is down on all fours and has his weapon removed from his waist band. Just a second later, he is shot as he tries to stand up after agents start moving back off of him. He falls back to the ground and another 9 shots are fired with out any command for Pretti to drop a weapon, put his hands on his head, get on the ground. He is shot multiple times in the back even as he laid on the ground.
ICE agents were not in the process of arresting or detaining anyone who was believed to be in the country illegally. They assembled into a large group and were armed with pepper spray and pepper balls in order to pick a fight with activists who were in the area. Pretti never approached agents or did anything to hinder anyone from doing anything. The agents charged him and a woman and started violently assaulting them for no reason. Pretti was murdered because in another incident in Chicago a woman was shot five times by ICE agents survived and is now trying to get a court order for ICE to preserve body camera footage. The agents made sure to finish off Pretti so that no one would show up in court to try and challenge them.