Stalkers

Ok so I have had a couple of stalkers in the past. Luckily one moved to a different state and I don't usually see the other 2. Well I now have a new one. I've known him for 3 years and only see him a few times each year for camp. He is a couple years younger than me but like 4 inches taller. He for the most part usually amuses me. He's funny, has a really good sense of humor and likes making me smile. Well he went a bit too far last weekend and took pictures of me without my knowledge. He also followed me around 2 hours before camp started. He's never bothered me before now cause he hasn't made his interest in me like super obvious. But this year he is dating someone and he knows full well who I'm dating. I don't know completely why he bothered me this year. I just don't really like people who stalk me. I know my boyfriend didn't like it and talked to the guy. It didn't stop my stalker from continuing to talk to me. He's one of those guys that if you don't say anything back to him he'll talk more and more. So I have to talk to him to get rid of him. Any ideas on what to do to make him back off a little and just consider me a friend or for him to go away completely?