Officers reported that several people began jumping over a fence when they arrived and, specifically, observed a group of five men attempting to jump over a fence and ordered them to stop, said Capt. Phil Trent, South Bend police spokesman.
Rees was the only one of that group who ran from the scene, Trent said.
The officer chased Rees around the home and ordered him to stop, according to a police report. When the officer tried to grab him, an altercation ensued and the two fell to the ground, Trent said.
On the ground, the officer allegedly was kneed in the abdomen by Rees, which knocked the wind out of him and led him to pepper spray Rees. Once in handcuffs, Trent said Rees still attempted to resist.
Calabrese, meanwhile, verbally reacted to the arrest of Rees and would not stand on the sidewalk when ordered to by police, Trent said.
Calabrese's friends reportedly attempted to hold Calabrese back, but he continued to yell things at officers that were interpreted as threats, leading to his arrest.
At one point, Trent said Calabrese told officers: "My people will get you."
Nobody else at the party was arrested, Trent said.
"These two guys probably had the most to lose, and (Rees) decided to run," Trent said.
Rees reportedly blew a 0.11 blood-alcohol content; Calabrese blew at 0.12.