WPVI-TV ( http://bit.ly/XYdMyz) says the 37-year-old victim had dropped off two of her four children at school and was walking home when a man began chasing her firing a shotgun.
Witnesses called police but they said the man caught up with her and shot her to death as she tried to get into her car.
A man was arrested after a chase by responding officers.
Police said the victim had recently broken off a romantic relationship and had obtained a restraining order.
Information from: WPVI-TV, http://abclocal.go.com/wpvi