She has been identified as Megan Nieberle, a nurse at Children's Hospital of Philadelphia.
Nieberle was found dead in her SUV after the shooting in Tredyffrin Township on Saturday night.
Police say officers had an interaction with the suspect, 44-year-old Steve Jahn, just two hours before the shooting.
Woman shot in Tredyffrin Twp. was killed in 'random act of violence': DA
Investigators said Jahn appeared to be experiencing a mental health episode.
However, he refused to be voluntarily admitted when officers escorted him to Paoli Hospital.
Jahn is now in custody facing a murder charge.
READ MORE: Tredyffrin Township police detail encounter with armed man hours before random killing