i'm in agreement with lazarus, criminals, especially the scum like child abusers and murderers, lost all rights as human beings when they literally or not destroyed someone elses life. who gives if they feel pain as a result of improved medical knowledge? they're giving back to society what they stole of some little abused kid or raped and murdered woman!
If criminals, instead of being financial burdens, can offer a purpose then why not use them, if without a doubt they are guilty of a murder then there is no reason not to use them for the good of society to help cure diseases and like wise...