A man goes missing. His family reports him missing. His vehicle is found weeks later, far away, with signs of foul play on it (his blood in the window's seal). The police search his home for clues to who might have had some reason to hurt him.
Would they need a warrant for that search, and if they found illegal drugs in that search could they arrest him on that evidence when he's eventually found?
just a "most probable" would be fine. I just don't want to have something really silly. As a writer, I don't want him to be arrested and if it's very likely, I'll have them be legal drugs.