Taipei -A schizophrenic Taiwanese man who decapitated a three-year-old girl in public on a busy Taipei street escaped the death penalty on Friday as he was sentenced to life in prison for what the court called an "appalling" crime.Wang Ching-yu, 34, had pleaded guilty to killing the child in a crime that shocked the generally peaceful island after overpowering her mother near a metro station.He beheaded the girl with a kitchen knife as horrified bystanders tried to stop him.Wang had told the court that he hallucinated he was a Chinese emperor from Sichuan province and believed that killing the girl would bring him concubines to "carry on his family line", according to reports.When asked in court if he knew why murder was wrong, he had said he knew he had made a mistake because no Sichuan woman had come forward to bear him children after the killing.Prosecutors called the crime "extremely cold-blooded" and demanded the death penalty.But judge Tsai Shou-hsun told a Taipei district court on Friday that he would instead be jailed for life as he had a "mental handicap".Wearing black-framed glasses, a white T-shirt and track pants, his head shaved, Wang remained calm as he listened to the verdict, responding: "I understand".The victim's family were not in court.In a statement after the verdict, the court said the decision was in accordance with international human rights covenants protecting those with mental illnesses.It said Wang had been expelled from school and had gone through drug rehabilitation, but was reclusive and isolated, developing schizophrenia and hallucinations.However, the statement also described the killing as "grotesquely violent", adding that Wang had known murder was illegal and had dodged supervision in order to commit it."He has not shown empathy and regret, and after assessment the chance of committing crime again is still high," the statement said.Death penalty debate Taiwan resumed capital punishment in 2010 after a five-year hiatus. Executions are reserved for serious crimes such as aggravated murder.Some politicians and rights groups have called for its abolition, but various opinion surveys show majority support for the death penalty.After the decapitation in March last year, hundreds of Taiwanese, many dressed in black and wearing stickers reading "Death penalty is necessary", called for Wang to be executed.The killing came less than a year after the throat of an eight-year-old girl was slit in her school restroom in Taipei. It sparked widespread public anger and fresh debate about capital punishment.Prosecutors in Wang's case said during court hearings that he should be put to death as a psychiatric report had found him to be mentally sound enough to be responsible for his actions.But his defence had argued that Wang suffered from a mental disorder, so should be given a limited-term imprisonment or sent for treatment, local media said.Police said he had previously been arrested for drug-related crimes. He was attacked by an angry mob while in custody.Prosecutors said blood tests showed he was not under the influence of drugs at the time of the murder.