Steve Jahn, 44, was arrested for the crime, the district attorney's office announced Monday.
Jahn is being charged with murder and related offenses.
Police responded around 10:45 p.m. Saturday for a report of a car crash at the intersection of Contention Lane at Old State Road in Tredyffrin Township. When they arrived, they found the woman behind the wheel of a silver Acura suffering from a gunshot wound to the head. She was taken to the hospital and died Sunday evening.
No further details were released about the circumstances surrounding the shooting.
The victim's name is not being released at this time out of respect for the family's wishes, D.A. Chris de Barrena-Sarobe said.
Neighbors described the incident as unsettling and unusual for this area.
"This is a quiet, residential neighborhood. Kids are out playing all the time, and to have something like this happen is really scary," said Pete Long.
"I wouldn't think in a thousand years that such a thing could happen in this neighborhood. We thought this was the safest neighborhood," added Nazli Torabi of Tredyffrin.
Jahn is being held in the Chester County prison without bail.
WATCH: DA de Barrena-Sarobe holds news conference on Tredyffrin Twp. shooting
D.A. news conference on Tredyffrin Twp. shooting
Detectives say tips from the community and surveillance video played a large role in quickly making an arrest. It is also helping them get a clearer picture of what happened, and they are asking anyone with more information to please contact them.