In early 2017, Karl Iscove was hired by Ricardo Diaz to kill Owen Post, specifically with a bow and arrow. Not long after that, Karl was also killed, presumably by Diaz. The surveillance footage of Karl killing Owen was then doctored to look like Oliver Queen in his Green Arrow suit did it. The video was later sent to Cayden James, which led him on a crusade to avenge his son's death.
- Skilled assassin: Karl was a known assassin who had enough skills to use them for living.
- Bow and arrow: Although not a part of his usual modus operandi, Karl used a bow and arrow to kill Owen Post.
- Although it was implied that Ricardo Diaz had Karl Iscove killed, the fact that Oliver Queen was well aware of Karl and his current status might be a sign that he had somehow crossed paths with Team Arrow previously.
Behind the scenes
- Karl's surname is a very likely reference to Robert Iscove, Canadian veteran television director who directed the pilot for 1990's starring John Wesley Shipp, Amanda Pays, and Alex Désert. The creative team of also did their own version with numerous references to the 1990s version, but it should be noted that inspiration was also evident in Season 1 of .
- It should also be noted that Barry Allen/The Flash made a brief cameo in the same episode as Iscove's first full appearance.