No students were harmed in last month's incident at El Sobrante Christian School on Argyle Road, but parents are concerned.
"I was extremely frightened once I got the call; I never made any provisions and worse it was somebody I didn't know, it was a complete stranger," parent Janea Faulk said.
Faulk says she was at work when the unidentified man told school administrators he was waiting for her so they could pick up her daughter.
"He knew who my daughter was; he stated her by name," Faulk said.
Apparently it was enough for the school to give the man a visitor's pass. Faulk says he never gave his full name and wandered all over campus before disappearing.
"How close was he to the students? He was actually within arm's reach," she said. "He could have touched the kids, and I heard from a parent that he was talking to the fifth graders."
Principal Scott Wells declined an on camera interview, but he says the school is now reviewing its office procedures.
"The kids were on lockdown, and they went ahead and alerted all of the parents," parent Tina Tranzor said.
Despite the slip up, Tranzor is satisfied with the school's response. They held a safety meeting Monday night. They also added more surveillance cameras and now require people to show identification to verify they're on a list to pick up students.
The Contra Costa County Sheriff's Department is still looking for the man.
