For the restoration of justice.
I run the Michael Stone website: http://www.ismichaelstoneguilty.info/
Michael Stone is the longest serving miscarriage of justice prisoner in the UK. He has been convicted twice of the Chilldenden Murders, the first time on the basis of concocted prison confessions, the second time on the basis of one confession he is alleged to have shouted through a cell wall.
Although Stone is the most high profile case he is far from the only one. Prior to the 1984 Police And Criminal Evidence Act, police officers would routinely "verbal up" suspects, especially those of bad character. When tape recording of police interrogations was introduced, verballing disappeared literally overnight.
We are now in the invidious position that the word of a convicted criminal, including persons of very bad character and with their own agendas or axes to grind, are held in higher esteem by the courts than police officers. If a police inspector or indeed a chief constable were to claim a suspect confessed to him in the back of a police car, this alleged confession would be ruled inadmissible by the trial judge. Whereas a convicted drug dealer or even a convicted murderer who claims the same confession was made in a police cell will be allowed to testify.
Prison and cell confessions are both extremely easy to manufacture and almost impossible to refute.
I would suggest that in future, before a prison or cell confession is admitted in evidence that it fulfils certain criteria. The famous "Christian Burial Speech" in Brewer v Williams, an American case in which an accused confessed a murder to a police officer while being transferred, is a good template for what should be admitted in evidence and what should not. In this case, the accused not only confessed to the murder but led the police to the victim's body.
In effect, I am arguing that no prison or cell confession should be admissible in a criminal case unless it adduces meaningful evidence not already in the public domain that can be proved in a court of law.