The pair is being held at the Eastern Regional Jail near Martinsburg, W.Va.
Carper said he has thought about what might have happened if he had not decided to get into his cruiser and follow the car.
The 23-year-old officer caught up to the Mustang on W.Va. 480 as it headed outside of town.
Carper said that he was thinking he would pull the car over, advise the driver that after-market exhaust systems are illegal, and issue a warning. He also planned to ask about damage on the driver's door to see if the car had been involved in a hit-and-run.
Carper said he waited until there was a shoulder on the side of the road and then turned on his flashing lights to signal the driver to pull off.
Instead, she took off, speeding down W.Va. 480, at a rate that quickly left the police cruiser behind, Carper said.
Carper said he thought over the dangers of chasing a car on a hilly, two-lane highway at night.
There are times when he's made the judgment call that a car is not worth chasing, Carper said.
"I knew my intuition was right about something," Carper said. "Every time she'd hit a hill she'd bottom out with sparks flying out from beneath," Carper said.
Carper said he tried to stay close enough to the car to follow its tail lights and radio the vehicle's location to headquarters.
He lost sight of the car, but a woman at a convenience store told him the car had turned right on W.Va. 9 and he radioed its new direction.
Jefferson County Sheriff's Deputy Mark Roby got behind the car and followed the driver into Berkeley County before the driver lost control and ran up an embankment on the Interstate 81 ramp.
Carper pulled up in time to see Roby putting the handcuffed driver into his cruiser. Carper joined in the foot chase for the passenger, who was caught by West Virginia State Police troopers.
Carper and Roby found a plastic bag filled with bloody clothes and began to piece together why the women seemed so intent on escaping.
"It was very fortunate how it unfolded," Carper said. "We were very lucky."