What about the debate on the release of life prisoners to provide space in the jails. Surely this isn't right?

I know I have already asked about capital punishment but heard today about the above and also the thought that life imprisonment should be 15 years maximum. I believe that this is ridiculous as that means that people can go out and commit murder (which affects the family of the murdered for the rest of their lives) and walk free after just a few years to possibly commit the same crime again. After all if a persons morales allow them to take a life in the first place they stand a good chance of doing it again. The only way to stop these people is to make sentences tougher not easier, in fact I believe that the best deterrent has got to be if you kill somebody then you lose your life as well. The idea should be to frighten people so they are in fear for their lives not just think they are to be locked up for a few years and then come out again. This would then hopefully teach them to have more value on the life they are about to take.