Catherine Kennedy was driving home from church when she landed in the middle of a gang shootout.
Caught in the crossfire, the 55-year-old youth leader was mortally wounded by a bullet to the head.
Barbara Allen said she was in her apartment about four miles from the Church of St. Timothy when she heard four gunshots followed by the sound of a crash. Allen rushed outside, she said, and found Kennedy slouched behind the wheel of her car.
She died at a hospital soon afterward.
"She was in a prayer group on Tuesday," her sister Deborah Ware said Wednesday. She said Kennedy's faith "meant everything to her."
A spokeswoman at St. Timothy's said Father Fernando Ramirez was too upset to comment, adding that "Cathy was one of the most wonderful people you ever want to meet."
Escondido police Chief Craig Carter called the killing "a senseless tragedy" and said his department would be cracking down on street gangs.
"We are altering our resources to address this," Carter said Wednesday. "If you are a gangster in the city of Escondido and you're contacted [by police] we're going to use the furthest extent of the law to make sure we deal with you."
Kennedy is survived by her husband, Kevin Kennedy, and daughter Alicia de la Rosa, 24.
5:50 p.m.: This article has been updated with additional details on the shooting and comments from police.