What are the fitness requirements for being a crime scene investigator?

I'm a 15 year old girl and I want to become a crime scene investigator. The problem is that I'm very skinny and short, and I think I'm supposed to be able to lift heavy stuff, etc. I could run after a suspect fine and everything, but tackling them or wrestling things away from them would be almost impossible (I try to do it to my dad %26amp; brother a lot). If I took classes on self defense would that be sufficent?What are the fitness requirements for being a crime scene investigator?A crime scene investigator usually doesn't have to run after or tackle suspects. So I wouldn't worry about that. What you'll need more than anything is a forensic anthropology degree. So concentrate on getting educated for now.