How old do you have to be to intern at a local police department?

I live in Massachusetts and I plan on going to college for criminal justice. In the fall I'm going to be a senior at my high school and talked to someone from a different town who interned at his local police his senior year. I forgot to ask him how old he was so now I'm here asking. I'm going to be 17 and was wondering if I could intern at my local police to get a jump start since the college I want to go to requires me to complete three internships and if I do this one now I won't have to do it then and I can intern at a more interesting position/more involved position.