Was Josef Fritzl, who kept his daughter (Elizabeth) in a cellar for 24 years and has confessed to fathering seven children with her, responsible for his actions? That is what his lawyer, Rudolf Mayer, said experts must decide. He faces up to 15 years in prison just for rape - if he is found guilty of rape. In an interview with the BBC Mayer said Fritzl will undergo several psychological and psychiatric tests.