A Philadelphia detective fired his weapon at three suspects as they beat their carjacking victim outside the driver's SUV on the 5100 block of Rubicam Street early Monday.
It is not known whether the suspects were wounded in the gunfire, NBC10 reports.
Police told NBC10 the carjacking suspects may have mistaken the victim for a taxicab driver after seeing him drop off his girlfriend at Broad Street and Allegheny Avenue about 12:30 a.m.
The men forced the victim to drive the SUV for nearly 3 miles, beating him along the way.
The detective came across the assault in the city's Germantown section while responding to another crime scene. He ordered the three men to stop attacking the victim, and he fired his weapon when one of the men pointed a gun at him, according to the report.
The extent of the victim's injuries was not immediately known.