She later added that Fox's wife is pregnant.
Fox and his canine partner, Nick, were shot about 5:45 p.m. on Conshohocken Road near Ernest Station Road in Plymouth Township.
The officer was pursuing a suspect in a hit-and-run crash and became involved in a confrontation with the man once he caught up to him, Ferman said.
Fox was shot in his head during the struggle. He was taken to Montgomery Hospital in Norristown, where he was pronounced dead.
The shooter fled on a bike path into Conshohocken, prompting authorities to shut down traffic in the area. SEPTA also suspended service on its Manayunk/Norristown line because the path the killer used to flee is adjacent to the train tracks, a spokeswoman said.
The suspect was shot and apprehended, and later died, officials said. He was not immediately identified.
"He was alone in the car, from everything we know," Ferman said. "There is no gunman out on the street, and the public can rest comfortably that there is no imminent danger to anyone out there."
Fox was one of only 25 patrol officers in Plymouth Township. He is the first township officer to be killed in the line of duty, Ferman said, adding that his canine partner survived.
Contact Phillip Lucas at email@example.com or 215-854-5914. Follow him on Twitter @UnPhiltered. Read his blog at PhillyConfidential.com.