The Blacklist

Agent Ressler is loosely based on Robert K. Ressler, a former FBI agent and author, who played a significant role in the psychological profiling of violent offenders in the 1970s and is often credited with coining the English term "serial killer". He was also fundamental in the setting up of the ViCAP system

Red's signature fedora came about as a result of a suggestion from series star James Spader.

Kiefer Sutherland was considered for the part of Red.