A Question For Those Who Have Been Stalked At Work!?

My friend's daughter is being stalked at work. She works the night shift at a coffee stand and a man much, much older than her has been coming by every night to talk to her. He's sent her flowers, given his number to her, he's pestered her into talking to him longer. More recently he's followed her half-way home and drove through the parking lot many times. He's been told by her co-workers that he's not to come by. He's had the police called on him by her, but he still comes. Just last night he called her work asking for her cell number and address, then screamed at her co-workers when they wouldn't give it to him. Her mother called the police again and let them know what's going on, but her daughter is only 19 and afriad he will snap and get angry. Can anyone give any advice who's been in this situation or knows someone who has been stalked at work? I want her daughter to trust the police to do their job, but she's scared.