I suppose an investigation that was legit would take a good hard look at the people and the habits around the VD house to start with. I don't believe that was ever done and Diane Halfman is largely the reason.
I would also look to see if anyone in LE was involved in the same swinging circles and may want to do anything to prevent exposure.
You tell me if it makes sense that these freaky perverts were cleared in record time. I have said it's like finding a murder victim with Jack the Ripper, the Boston Strangler and the Nightstalker living in close proximity. Look right past them and go for the quiet guy up the street with absolutely no relative history. It makes no sense to me.
Westerfield was zeroed in on too quickly and likewise others were ruled out in a foolishly rapid manner. As a result, we may never know the whole truth of what happened that day or night.
Remember that Damon is the only one who has to vouch for himself for a number of hours. Add to that the fact that he was overheard telling Brenda in a radio interview not to talk about the timeline. Need I go on?
Who is she and what bearing does she have on the case?
And FWIW, how is it you think of Westerfield as the "quiet guy up the street"? Was he not involved in this whole "swinging" crowd?