Putting the weed in brownies is equivilent of storing your liquor in a pop bottle, or mixed with the jug of Kool-Ade.
It isn't the possession that is the problem; it is the "storage" method that is the problem here.
Reminds me of when my dad put Ex-Lax in the Hershey's wrapper, then TOLD his Bedouin laborers that it was "his medicine" and that it WOULD make them sick if they stole & ate it. He never had his candy bars stolen from his lunchbox again!
You clearly haven't tasted some of the premixed liquor in beer sized bottles with the cool beach pictures on them. They taste like KoolAid too. No joke. A kid could drink 3 of them and be wasted.