Prison rights?

my spouse is in prison for something he didnt do.....he was at the wrong place at the wrong time and he got charged with the case alone with other people........first offense and he recieved 4 years......for a non violent crime instead of putting him on probation and allow someone who is a rapist or killer take his spot in prison.......they put him in there.....i do believe he should have to pay his debt to society. but he could do that on probation and do communtiy service at a drug rehab or something.