I can definitely help you on the presentation/essay (however I think a lot of my case law comes from Canada, so I don't know how much that will help you - my knowledge is universal though! -hehe jk).
Er...for your intro paragraph (nice job on the procrastination, btw, coming from someone in the know)...first talk about the implications of teen sentencing. Why should it be done? Why shouldn't it be done? Don't even just limit it to horrific crimes. Also consider crimes where it's a repeat offender. For example, in Vancouver, we had this kid who was 12 years old and he stole 60+ cars. And every time the cops caught him, all they could do was take him home. The kid himself actually told the cops he was untouchable until he's 14. The kid's a sociopath who knows the system - his crimes aren't horrific, but he won't stop stealing.
"It's not always about you!!!" (But if you think I'm referring to you anyway, then I probably am.)
"Good luck returning my ass!" - Wilhemina Slater
"This is my breakfast, lunch and f***ing dinner right here. I'm not even f***in' joking." - Colin Farrell