Perez, 28, was killed by a bullet to the heart. Two other bullets hit him in the left arm and left side of his chest. Dr. Larry Lewman, deputy state medical examiner, said Perez had an "extremely high level" of cocaine in his system. Police radio logs show the shots were fired 24 seconds after the officers called in the stop.
In a statement, the Portland Police Association called Sery a calm, professional police officer who acted with reason. The union noted that the American Legion recently named Sery its "Officer of the Year."
"Like all police officers, he hoped the day would never come when he would have to use deadly force," the statement said. "Our shared tragedy today is that Mr. Perez's actions gave Officer Sery no choice."
The union's statement added details about the stop. It said Perez refused an order to put his hands on his head and shoved his right hand into his pocket.
"Every bit of Mr. Perez's conduct, every bit of Officer Sery's training, told him that Mr. Perez was about to shoot him," the union said.