He was in a townhouse across the street from an acute care center. They (NBC Bay Area News) are talking to a woman who works at the care center. She saw the van with the sticker in the window and remembered the CHP announcement of the possible vehicle. She looked in the window and saw a baby seat in the car and called police -- they told her to get away from the van, that they are on their way. Reporter said that suspect who was arrested matched the video.
The suspect mentioned before who was being questioned at the police station is a woman who had been shopping with the grandma and her stories had been inconsistent. NBC doesn't know yet what her connection is with the kidnapper, if any.