My work best friend wants to dress up as jeffrey dahmer for halloween

To the strip club halloween event and we will have loads of customers in , its an working night still and I honstely dont know how I feel about that. Im into the psychology of serial killers but I feel like they shouldnt be glamourised as they are very mentally ill so I dont really know how to react to her openly telling everyone at work shes going to do that. She was being serious too. I feel like its disrepectful to the families of the victims even though they dont know shes doing that. I dont think it will go down very well to be honest if she goes through with it and I dont want her to get into trouble. I dont know how people will react to that , I hope she doesnt go through with it as I think she will cause so much trouble at the club. I havent talked to her about it as I dont want to come across as dictating. What do you think about it ?