If he actually did it, he should rot in jail like any other murderer. If it can be proven that he didn’t, he didn’t he should walk free. That’s how it should be. That is how civilized people work.
I think you got it a little mixed up. The state needs to have it proven that he did in fact commit that murder, and not leave any doubt about it. It's really not his job to prove anything, let alone that you can't prove innocence in a lot of cases.
That argument is stupid, because usually people need a reason to save for. Now rent is so high that people can barely save, and houses are so expensive that even if they do and get a credit with their staggering student debt, they'll never be able to afford it.
So what do people do? they just enjoy the small things, because they know they'll never have the big ones.