I think it’s very hard to say, and it just gets harder the more I think about it (like many things tend to).
On one hand, if the condemning evidence can’t be provided by someone other than me, should the case be prosecutable?
On the other hand, any sentient human can come up with examples of cases where it might be reasonable to search my belongings for evidence; multiple independent witnesses point to me being guilty of murder and investigations have otherwise stalled. Or anything of the sort.
What if all the independent witnesses are not independent? What if I’m not the guy, but just a lookalike? What if I’m being set up by the authorities?
The easy thing to do here is to say well okay SOMETIMES it’s okay to search one’s belongings but not for like any silly reason or anything like it has to be a real serious one. Then it’s just a matter of where to draw the lines, and who should get to decide.
I like the more absolute stance I made earlier; the government shouldn’t have any business in my personal belongings. Some crimes will go unpunished and that’s a price I’m willing to pay.