The denial of a prisoners right to vote does essentially nothing in deterring crime. Inmates are indeed citizens who have failed to follow societal regulations, but they are still inherently citizens. They have the right to express their personal opinions by way of voting. Now, it not within my knowledge that these rights are waved upon conviction, but if they are not, then they should be able to vote.
History has shown that prohibition and revocation of rights does not prevent crime. People, have been killing, cheating, and raping each other since the dawn of man. In every society, even those where the only punishment was death, people continued committing crimes. The right to vote has little to no bearing on the crime rate,