A French prisoner dubbed 'Hannibal Lecter' was on Thursday sentenced to serve another 30 years in jail for killing his cellmate and devouring his lung. Nicolas Cocaign has admitted to beating and stabbing Thierry Baudry with a pair of scissors before smothering him with a rubbish bag in the prison in the northwestern city of Rouen in January 2007. In a sensational four-day trial, the 38-year-old testified that he cut open Baudry's chest with a razor blade and ripped out the lung, eating part of it raw before frying the rest with onions on a camping stove in his cell. The court in Rouen followed the request of prosecutors who had asked for 30 years with no possibility of parole for 20 years. 'A man who plunges into horror is not necessarily afflicted with madness,' prosecutor Elizabeth Pelsez argued at the close of the trial, echoing the view of a majority of psychiatrists who testified in court. The defence countered that he should be declared criminally insane and declared not guilty. 'He killed him because he is mad, totally mad,' said defence lawyer Fabien Picchiottino, addressing Baudry's mother in the audience. Cocaign, whose face is tattooed with a skull, told the court this week that the murder might have been avoided if prison authorities had not ignored his repeated appeals for psychological help. 'No one was listening to me,' the defendant said. 'I made several appeals for help, saying I was a man capable of being dangerous. I took action, and then they took me seriously.' In his final arguments, the defence lawyer stressed that the case had highlighted 'the failure of the system' that failed to take seriously several warning signs about Cocaign's mental state. Baudry's mutilated body was not discovered by prison warders until the day after his death at the Rouen jail, which has been cited in court rulings for its decrepit and overcrowded conditions. In demanding a 30-year sentence, the prosecutor stressed that Cocaign was not only charged with murder but with torture and committing barbaric acts. 'This not the usual type of violent act that might take place during a scuffle or a fist fight,' said Pelsez. Cocaign's case has prompted comparisons with the serial killer character Hannibal Lecter in the best-selling novel and movie 'The Silence of the Lambs.' He was in jail for armed robbery and was awaiting trial for attempted rape at the time. Baudry was serving time for sexual assault. A third cellmate was probed over Baudry's death but cleared of any wrongdoing. He later committed suicide. 