Putting people in prison for unrelated things is a normal and celebrated aspect of the American legal system. I don't mean celebrated in some metaphorical sense, either. I mean it is actually celebrated in American culture. Think "Al Capone went to jail for tax evasion".
Maybe that's not a good thing, but it sure worked in this case.
I through that Al Capone really engaged in tax evasion. Even as he did much worst things, if he was really guilty of tax evasion, then it is perfectly ok to put him in prison for tax evasion. Putting people to jail for things they are not guilty of just because they did something else bad is injustice.
Putting people to jail for things they ARE guilty of is fine even if that is not the worst thing they did.
Maybe that's not a good thing, but it sure worked in this case.