DNA has to be collected somehow. If the perp uses a gun and never goes near the victim, it's rare that there's DNA to match. If the perps were inside the van, though, it's *possible* some DNA would be found (but really, it takes a special forensic team a lot of time to swab all the possible places; fire makes it much more difficult, as we learned in our Cali wildfires). If the perps dragged bodies out of the van before burning (as it appears they did), then...yes...they may find samples at the morgue. Maybe. The analysis of "found DNA" takes some time, though. They'd be looking for as few as a couple of cells on a body, and it's rarely done with bodies - usually with an inanimate object known to have been used by the perp. The clothing of the victims might yield this type of evidence, but it's like looking for a needle in a haystack. Even partial nuclear DNA evidence can be fairly identifying, though.
I just doubt that they've done that kind of analysis of the victims' clothing. I haven't seen pix of the RAV4, but if it were completely incinerated, it would be very difficult to find much DNA. Very frustrating for those tasked with that. I am guessing that's RCMP lab work - done in some central location. To accomplish it in the best way, the lab should move operations to the car...sampling here and there might not do it.
