The former The West Wing Vice President was promoted to portray Ronald Reagan in a new TV adaptation of Bill O'Reilly's book Killing Reagan and his new project has hit the headlines following news the man who shot at the late U.S. leader in 1981 is to be released from the mental hospital which has been his home for the past 35 years.

The moment Reagan was almost killed by John Hinckley, Jr. features in the new film and Matheson admits director Rod Lurie wanted the shooting of the incident to feel as real as possible - and he wanted his leading man to feel as surprised as Reagan was when he was attacked.

"Rod would not allow me to meet Hinckley," the actor tells Entertainment Tonight.

Kyle S. More, who plays the would-be assassin, bears an eerie resemblance to Hinckley, and admits he made security on the set a little nervous.

"On the second day of shooting a security guard... stopped me and she was like, 'Who are you looking for?' he recalls. "I was like, 'Well, your instincts are great because you probably should stop this guy!'"