The husband and wife duet broke up both professionally and personally after Patty became one of Bob Crane's many romantic conquests in the mid 1970s. Sean was questioned several times by police in connection with Crane's subsequent bludgeoning death in 1978. Over advice of counsel, Sean O'Sullivan freely admitted to the investigating detectives that he "wanted to pound the hell out of Crane" not only for ruining his marriage, but videotaping the infidelity.

Given the number of angry husbands and boyfriends of the women Crane seduced, detectives had become used to hearing such comments. The murder case remained open until the mid-90s when a long-time friend of Crane was tried and acquitted.

Curiously, during the trial, the defense never raised one highly disturbing fact. For years after Crane's death, Sean O'Sullivan would visit the grave site on June 29th -the day of the murder- and break into a huge grin and sing "When Irish Eyes Are Smiling."