A serial rapist was jailed for life yesterday after a judge deemed his sex attacks on three students the work of a 'truly evil man'. Cheung Lai-man, 34, showed no emotion as he stood in the dock while Deputy Judge Alan Wright passed sentence. 'I realise that the sentences about to be imposed are enormous,' he told Cheung in the Court of First Instance . 'I realise equally that they are commensurate with the enormity of your crimes. You are a truly evil man.' Cheung pleaded guilty to three counts of rape, carried out between November 1997 and May last year while the victims, aged 12, 20 and 21, were on their way to school or university. The court heard Cheung videotaped the brutal attacks, which occurred at knifepoint in bushes along a footpath in Sha Tin, Tseung Kwan O, and in a make-shift shelter on a Sha Tin hillside. On each occasion, Cheung pounced on the girls wielding a knife and wearing a balaclava. He then bound them, blindfolded them and threatened to kill them if they refused to submit. 'I doubt that any man can clearly comprehend the effect of rape on a woman,' Deputy Judge Wright said. 'The injuries extend far beyond the psychological harm to the girls.' In imposing a discretionary life sentence on Cheung, Deputy Judge Wright set a minimum term of 20 years before he could apply for parole. He cited material from reports completed by three psychiatrists and a psychologist that found Cheung was a psychopath who would remain a danger to society. They also found he was not suffering from a mental illness but had a personality marked by self-indulgence and a callous disregard for others. One psychiatrist also found that Cheung's behaviour was inborn and not the result of his upbringing. 'I am satisfied that the reports say that you are unstable . . . in the sense of a dis-social personality,' Deputy Judge Wright said, adding he accepted Cheung was a real and continuing danger to society. 'If I err, it is better that I do so to your [expense] rather than to some girls.' Before sentencing, Cheung addressed the court and told Deputy Judge Wright that he 'really deserved this'. 'I am willing to be punished for life in order to make up for the damage done to the victims,' he said.