You said: "I regret assuming the hubristic moniker "CrimeSolver" " - don't put yourself down, your'e just trying to help, in whatever way, those who have suffered great loss... which is a good thing.
Your "drifter" theory is something to be pondered. But the question I ask is motive: Why a random murder(s)? No sexual assault apparent (victim's clothed), unless the shooting was a result of the girl's resistance and the killer(s) frustration with getting the girls to capitulate. How, then, were the girls lured to the vacant lot, if not promised to obtain some pot? According to newspaper articles, the victims were known to smoke it occasionally and, in the 1982 article by Max Haines, police (at that time) believed that drug angle to be most likely. Also, the bodies were left in a configuration - side-by-side linear fashion, head-to-foot, face-up-face-down - hinting at, not only at audacity and bravado, but also a signature to mock the police... that is why I asked earlier (to the person who went to school w/Donna) if this was a gang related thing. Would a murderous drifter, whose psychological mindset likely was animalistic in instinct and proclivity, have the intellectual flamboyance to put the victims in those positions. Moreover, the shots were fired adjacent to a residential housing area. Hence the "loud bangs" heard at around midnight. That's a "lets get the hell outta here" situation. As such, it would have taken some time, and some steely patience or resolve, to place the victims in their positions. Thus, I would say the resolve to configure the bodies after the evil deed was committed was (a) the result of "safety in numbers", peer pressure, proof of worthiness - thus a gang or (b) or by a very sly, charming and smart SOB who gave the appearance of harmlessness and trustworthiness - thus a single person... but again, the motive issue comes again into the picture... and how did the girls eventually meet up with him? Or her!!!??? Big mystery here. Finally, I would be disinclined to believe the murderer to be a trucker. I base this on a TO Star article I cam across (not indicated on the website of the victim's sibling). It shows a map similar to the one on the TPS website. It has one denotation saying that a dark coloured vehicle was seen exiting the lot at around 12:05 am, heading in an easterly direction along Wilson Avenue....