I believe there is a connection to the strip club. This is why.
There were more than a few woman that disappeared from the area surrounding a few strip clubs that have been discussed, although not positively connected.
The $20.00 bill that was found at the crime scene to means one of two things. Either it was a symbol of tipping at a strip club, although Cheryl worked as a waitress at the strip club, ( but not at the time of the murder) or whoever did this, thought Cheryl/Andy ripped him off for $20.00 at Bayou Mama's, and that upset him.( motive) I was wondering if Cheryl and Andy and her Sister sat at the bar rather than a table at Bayou Mama's. If they did, imo, someone may have left change on the bar and someone other than them could have grabbed it, and he thought it was Cheryl, or Andy. The only flaw in the latter thought is unless he paid with a $50, or $100 bill, I see no reason why he'd have a $20 laying on the bar.
Another thought...
One thing that would help is if we knew if the pilot boyfriend of the woman that was raped hung out at the strip club where his girlfriend worked. The rapist knew who he was, and I believe if the bf did hang there, the rapist may have sat next to him at the club, struck up a conversation, and gathered the information on when he was leaving for his flight etc.