being against CP isn't about the rights of the murderer. it's about the rights of innocent people being compromised in the case of mistaken judgements and if you look up the figures you'll find plenty of instances of this and our technology has not evolved to a point beyond making mistakes. the other reason is that the state should not be allowed to commit murder. when it has that perogative you will find examples of the death penalty being used for political purposes. think about blacks in the south before the civil rights movement. many cases of CP used as a political tool. none of my opposition to CP has anything to do with extending "extra" or "special rights to a murderer".
and to add to that, i also believe that he who kills a murderer is also a murderer no matter what "belief system" allows you to think that it is a justifiable act. the only acceptable standard to me is actual self-defense in which you face an immediate threat not the construct that says sentencing by a judge constitutes "societal" self-defense. removing the offender from society for life is the defense i advocate. when the law doesn't accomodate that we need to change the law.