Leonadro DiCaprio...why is he good for this part?

Hi, ok so tommorow im have to an oral presentation about a book we read in cl. Its called the sniper, and we had to pick three people who we think would play the parts well. I picked leonardo Dicaprio as the lead sniper, and I have no clues to back up why I picked him and Im freaking out because I dont want to get embarrased in front of the hole cl, when the teacher ask qestions on why I picked him. Can you please help me oby giving some reasons why he would be a good actor to play a part like a sniper. Please, Please, Please!