Authorities said Singleton ran from a vehicle that was stopped by Officer William Anderson on South Kirkman Road. The driver of the vehicle, 17-year-old Edward Kelty, struck and ran over Anderson seconds after Singleton fled, according to police.
A third suspect in the vehicle, 17-year-old Angel Nieves, was arrested and charged with tampering with evidence.
Investigators said Anderson opened fire after he was hit by the car. Kelty suffered a gunshot wound, and police said Nieves took the wheel and drove him to the hospital.
Anderson, who was working off-duty at the time, initially pulled over the car in connection with reports of shots fired near an IHOP restaurant, police said.
Nearby resident Scott Simas said he was awakened by the gunfire.
"There was one gunshot, and then about three or four minutes later, there were three shots," Simas said.
A police report says that another officer was responding to the IHOP restaurant, but diverted from the call to help Anderson.
Investigators said they were looking for several vehicles involved in the IHOP incident, but it's unclear if any of them have been found. Police have not said if the three suspects pulled over by Anderson were spotted at the IHOP around the time when shots were fired.
Anderson was first transported to Orlando Regional Medical Center after being struck by the car. On Thursday, police said Anderson's injuries were so serious that he was taken to UF Health Shands Hospital in Gainesville.
Kelty has been charged with attempted second-degree murder of a law enforcement officer and resisting arrest with violence. He is being held at the Juvenile Assessment Center.