in addition to the above, you need to document his/her behavior. keep a journal; take pictures and record phone calls and messages; note witnesses. With this type of documentation, the police can arrest him/her.
tell he/she that their behavior is really making you uncomfortable. If that doesnt sink into their skull, take out a restraint for your own protection ASAP! I watch the news, you never know how crazy a person really is. Be smart and safe.
First you need evidence they are stalking you. Keep a journal about every time they come around you with the date, place and timer, this can be used as evidence in court. Be sure to list any witnesses, who see the stalker there too.
Take as many pictures of the stalker as you can, these can be used as evidence also. Then when you have enough evidence, about four weeks worth, go to the police and put in a police report and let them take a copy of your journal and the pictures. Do not give them the originals, they can lose them sometimes.
But if the stalker is threatening you, you need to get a recording of their threat or take their threatening letter or card to the police immediately. Always take every threat seriously and stay safe. Always keep your cell phone with you anywhere you go. Good luck and take care!