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From Complex's interview with 50 Cent:

Complex: Shifting gears, in your VH1 Behind The Music episode, there was a part that talked about Diddy taking a meeting with you, and him getting shook because you brought a gun to the office…

50 Cent: This is what happened. Jennifer Lopez told Puffy that I was a great writer because Corey Rooney signed me to Columbia Records. Jennifer had been exposed to my material, so she told Puff she thinks I’m somebody he should work with. I came down to write and I was in there writing a couple of joints and Puff left the actual room. There was rustling and rambling at the door and s*** like that. I jumped up—when you get hurt as bad as I got hurt, either your fear consumes you or you become insensitive. So I jumped up and figured “as you come through the door, I’ll shoot your a** down right there in the door.” The paranoia heightens your senses. You start to see every little detail, every little thing. You don’t want to miss anything and have it turn out there’s someone shooting you again. When I heard the rambling outside, I jumped up, I had a Mac-10 on me. Pulled the joint out and Puff came in and looked, said, “Oh s***, I can’t do this.” As a matter fact, it was Shyne and Wolf, wrestling outside. Puff was going through that actual case when he called me in to write and I’m in his office with a Mac-10. He was like, “I can’t do that.” After the fact, I looked at it and was like, That’s a legitimate call.