I don't find it that odd? Lost of people take stuff to someone elses house.
Amazing coincidence ... I find it odd. I have all three of those items but I have never ever brought all three to someone else's house on a causal visit. I might bring them to Starbucks if I have work to do and I am away from home and staying somewhere where there is no good wifi (like a hotel).
NOW, in the context here, it may be considered a criminal tool, yes, but PC is still needed to take it, right. They just can't take a persons cell phone etc., just because it is on the compact premises, right?
Which is precisely why I suspect the police know more than the OP is revealing, or that the OP knows. Unless the OP's local police are dunderheaded morons or they know a wee bit more about what is going on. If they are idiots, they might assume that anything on anyone inside the residence is fair game ... if they are idiots, I doubt they would have known how to write a decent search warrant and the whole case will get quashed.
I suspect there is more to this than meets the eye, or the police have some reason to believe that to be the case.
The OP is either more deeply involved than he is letting on, or the police have reason to believe he is. I doubt the items were sitting in a backpack he had brought inside only moments earlier.
No matter, if they were seized via search arrant the police cannot release it.
He said he was charged with unlawful possession of MJ, yes.
There may be more charges.