This 2010 endeavor stars William Forsythe, who does an outstanding job playing psychopath John Wayne Gacy. Forsythe also starred in Rob Zombie’s Halloween (2007) as Ronnie, the boyfriend of Michael Myers’ mom Deborah. Dear Mr. Gacy is based on the real life experience of 18-year-old Jason Moss. In 1993, Jason contacted Gacy (and other serial killers)…