I walked in the room, it was filled Texas Rangers and SWAT guys, and apparently I was wearing the wrong kind of shoes," Hall says. Kyle wasn't talking to him. Finally, after getting teased for a few nights, he took matters in his own hands and put one of the jokers in a headlock, wrestling him to the ground. That ended up being the introduction the steely military man needed. A friendship was born. It was brought to one of the producers, Peter Morgan, and myself from a guy that Chris worked with, Daniel Loeb. I looked into the story and heard that he was the most lethal sniper in history; he'd also hit an impossible shot at 2100 yards. It was so crazy sounding that I reached out to a friend of mine who used to be SEAL Team Six and is now working in the CIA. He told me, "I think the guy you're talking to is full of shit. There are only five guys in the world who have hit that kind of shot and no way he's one of them." About a week later, he called me back and said, "Your guy is one of the five." I knew I had to meet Chris, so I booked a flight down to Texas. It went from there. I knew there was a great story there but I didn't know exactly what it was yet. I knew I had to get inside his head a bit. He was a quiet dude, he'd smile and shake your hand but there was something behind the eyes that he wasn't letting on — like part of him was still at war. I wanted to get him to open up but it felt hopeless; I actually called my wife and told her I was coming home early. Then, before I'd left, I got to see him with his wife and kids. His eyes lit up when they came in and suddenly, I had an idea on who this man was before going to Iraq, and what the war took from him. I also caught a glimpse of what his spouse had gone through, raising the kids on her own, and that's where I saw what the movie could be about. He was a pretty quiet guy. When we hung out with his old buddies they'd tell stories, and I'd chipped away at his shell a little bit. But there was still a lot that I knew I probably wasn't getting out of him. You're a different guy when you're with a group of your boys. When I spent time with him and his family there was a different side of him. He told me after I had spent a good amount of time with them and was about to leave. He said, "By the way, they're doing a book on me too." I thought it was going to be an issue for the producers and myself, so we stayed in contact with him and his co-authors. We got an early copy of the book and were a worried about it getting picked up by another studio, but it didn't draw the attention that we'd been expecting — probably because it seemed more controversial than most studios were willing to be.