In 2021, actor Cassandra Peterson, who is primarily known for her alter ego Elvira, Mistress of the Dark, said in her memoir Yours Cruelly, Elvira: Memoirs of the Mistress of the Dark Chamberlain had sexually assaulted her during a party at his mansion in the 1970s. Chamberlain supposedly forced Peterson to perform oral sex after offering to show her a closet containing his NBA jerseys. Peterson stated she had blamed herself and was almost "convinced that I was a very bad person for letting that happen" until the Me Too movement made her reconsider the experience. Peterson felt the assault was "creepier" because Chamberlain had been a friend.
