As far as I know many of the 'facts' of the case are based on very slender evidence (of course LE must have much more).
1. Yorkdale: I think we only know that they planned to go to Yorkdale not that they went to Yorkdale.
2. The receipt from the College Yonge store for the gift for the sister. Was the gift found as well as the receipt?
3. Someone seeing them at Lawrence and Wilson one acquaintance and maybe the bus driver?
4. I only remember ONE person remembering seeing them at the restaurant though a recent interview with the detective seems to make that plural. But I think only one unless LE knows more which they might.
5. So the gun was used in a crime around Windsor used in this crime then found by the road out towards Windsor. Strange it was found there. I don't know what the basis for the biker gang theory is. I realize there was a similar crime out towards Windsor I think the town was Tilbury , two girls murdered. It is slightly odd there is a Tilbury Street near this crime scene but I doubt bikers reference other crimes in such an oblique way. I am wondering what evidence they have of bikers involved.
6. Time of the shooting I think is one person in the adjacent house to the crime scene and possibly one other person.
7. One person only I think hear a car hurriedly leave the crime scene area. Note they are not on bikes!
It is interesting that the detective says they are DNAd 70 people or so over the years. That suggests it is not new technology but rather hold back info they kept to themselves. Also that is a lot people. Some would be obvious, boyfriends etc. Perhaps a lot of sexual offenders?
8. The police/media rollout of the sexual assault info was poorly handled. No suggestion it was new. This should have been a big story.