Apparently, Netflix didn't contact Jeffrey Dahmer's father, Lionel Dahmer, prior to the series' release. At least that's what he claims.
In an interview with the US Sun , Lionel Dahmer's supervisor commented on the current events surrounding serial killer Jeffrey Dahmer. His employer Lionel Dahmer is already 86 years old and does not want to take a stand himself. However, his supervisor says on his behalf that Netflix is now planning to sue because the company did not ask Dahmer's father for permission to film the series about the Milwaukee killer.
BuzzFeed knows why Jeffrey Dahmer's dad is a "nervous wreck" because of the Netflix series.