The officer was under attack after a chase ended with a fight between him and two brothers. Michigan State Police Lt. Melinda Logan told the Detroit Free Press that "without them, I don't know what would have happened to the trooper."
The video starts with Trooper Garry Guild in pursuit of a man on a stolen motorcycle. The trooper wasn't aware that it was stolen at the time, but had clocked the bike at 150 km/h. The man crashes the bike but runs toward the officer instead of surrendering. Trooper Guild subdues and is handcuffing the man when a car enters the frame and a can (I'm going to assume it's beer) is thrown at the officer.
The passenger of the car, reportedly the first man's brother, jumps into the fray and puts the officer in a headlock. The two men fight with the trooper, injuring his neck and jaw and causing the trooper's gun to get lost in the scuffle. But then, just as Guild was "gasping and struggling for air, to the point where I can't breathe," two more people arrive.
Fortunately, Keith Pepple and Jerry Burnham were on the side of the law. They helped pull the brothers off of the officer and helped pin the pair down until Trooper Guild could handcuff them.
Pepple told the Detroit Free Press that "I guess everything happened so fast, you don't really have time to think about it. I just saw that he needed help. And I decided to help."
The trooper was back at work the next day, and the two brothers were arraigned on multiple felony charges.