lol, yes, undoubtedly gang shootings are influenced by 50 cent and gangster rap... espcially now... seeing as everyone views 50 cent as a gangsta rapper.
As for the whole movies influencing people to kill, i recall something i read in a paper or saw on the news about some bloke killing a small number of people because he was afraid they were going to turn in Agents from The Matrix.
In my oppinion people don't kill because of movies, music or books. If a person has an inclination towards murder then he's going to kill someone, maybe movies or music just give him/her an idea as to how to do it in a more interesting way. And as for violent games causing violence, isn't that just the governemnts argument to put a ban on violent video games?