Getty Images Suffolk County Sheriff Errol D. Toulon Jr. has supervised a number of infamous criminals over his career, including John Gotti , Bernhard Goetz , and even “Preppy Killer” Robert Chambers. Still, Rex Heuermann —who pleaded guilty to seven murders and took responsibility for another death as the Gilgo Beach Killer on April 8—has managed to stand out in one haunting way. “I can tell you the one thing that’s different about Rex Heuermann than all those individuals is that, at some point, I did see some despair in those individuals when they were in their cells,” Toulon told News12 reporter Cecelia Dowd. “Yet every single time I have walked into that housing area and toured and saw Rex Heuermann, there seemed like there wasn’t a care in the world and also a little bit of smugness about his demeanor.” His infamy now sealed, Heuermann awaits his ultimate fate—expected to be life in prison—at his sentencing scheduled for June 17.…