BBM
If he transported her deceased body in his car wouldn't the scent have been picked up by cadaver dogs?
Not unless blood transferred to the truck/car and then decomposed there. Cadaverine isn't usually produced in the first 12 hours of decomp, perhaps even longer (depending on temperature). Forensic textbooks usually say it's not detectable until at least 24 hours.
Several drops of blood, decomposing, would alert a dog that the blood had been deposited very recently. If it's then found to be Suzanne's blood, that would be a significant clue. If somehow the body produced lots of blood that remained in the truck, then, well, I think BM would be in custody. That would be a really dumb and sloppy move on the part of any perp.
I don't think he put her in his truck. If he did, it was right after her death. Since he probably doesn't know much about cadaverine (just my guess), he would not want her in the truck for very long. So in this scenario, I don't think he traveled hundreds of miles with a body in his truck.
At any rate, cadaverine is still in very low (or zero) amounts for the first 24 hours. Dogs are very good at picking it up after the 48-72 hour mark. I was about to go into further detail, but it occurs to me that some things need to be left untyped in a public forum.
But Patrick Frazee transported Kelsey's body in a container and I don't believe they ever found any cadaverine in his confiscated vehicle (maybe someone else will know, who followed the trial more closely than I did). That container was stored in Frazee's barn, IIRC, and dogs did pick up scent there (again, IIRC - which I may not be).
To me, the staging is designed to explain why Suzanne's body will eventually be found in water. Just a hunch though. There are people who disappeared into a similar river flow in the Merced (the only river I'm very familiar with) and never found or a skull found years later. If we see investigators revisiting the South Arkansas River and the intake area to the dam, again, I wouldn't be surprised. OTOH, if they are unable to find anything, it wouldn't be the first river disappearance of a human body.
General question. What could you do to a body to keep it from being scented or had the scent transferred to something like in a pickup bed? I'm not certain even incineration would work if it was recent. Lime? Space blanket? Add an animal carcass?
Animal carcass wouldn't work if there was any human body fluid/blood in the vehicle.
There's nothing anyone can do to prevent a body from decomposing, except freeze it. However, as I mentioned above, cadaverine (what dogs sniff) isn't produced immediately. So the idea would be to get the body in and out of the vehicle before the 12 hour mark, preferably making sure no body fluids escaped into the vehicle.
Incineration would work, if it was complete. I can't find any cases in the forensic literature where cadaverine was used to locate a burned body. But the key thing is time. Cadaverine doesn't appear in the products of cells right away. Complete incineration is of course quite difficult (usually teeth remain as well as thicker bones, such as the back of the skull - even in very hot fires such as the ones that swept through Paradise, CA). It can be very difficult to locate incinerated remains if the perp is aware of this.