DALLAS — A Dallas police officer fired four shots after mistaking an undercover officer for a suspect during the arrest of a man accused of vehicle theft, the department stated. During the felony traffic stop, a covert officer positioned his unmarked vehicle in front of the Porsche to prevent the suspect from fleeing. As the covert officer moved toward the yard, Officer Celso Rocha fired four rounds toward him and the suspect. “Blue, blue, blue,” another officer shouted from a distance. “When you talk about a ‘blue on blue’ shooting, it’s unfortunate,” Comeaux said.