Attacker was sleepwalking, court told

PUBLISHED : Friday, 23 November, 2007, 12:00am
UPDATED : Friday, 23 November, 2007, 12:00am

Prostitute acted out a violent dream, says psychiatrist

A woman who stabbed and tried to smother her friend was most likely sleepwalking at the time of her attack, the Court of First Instance heard yesterday.

Two psychiatrists told the court that in their opinions 30-year-old Zheng Wei-dong, who has pleaded not guilty to a single count of attempted murder over the attack on December 15 last year, was not conscious of her actions during the 'unprovoked, frenzied and vicious attack'.

It is alleged Zheng, who worked out of a so-called one-woman brothel in Lockhart Road, Wan Chai, attacked her friend, surnamed Yang and also 30, with a fruit knife before trying to smother and then strangle her. Ms Yang also worked as a prostitute in the same complex as Zheng.

The court has heard that Zheng's story is that she cannot remember any details of the attack. She has consistently told police she can remember going into Ms Yang's room and offering her a slice of pear, an offer that was rejected. Immediately following that, Zheng contends, she became unconscious, only coming around a little later with her own body aching all over, her left hand bleeding, and Ms Yang fleeing the room covered in blood.

Yesterday, Yuen Cheung-hang, chief of the Department of Forensic Psychiatry at Castle Peak Hospital, said that based on a review of the facts and interviews with Zheng, he believed she had been in a state of automatism - basically sleepwalking - during the attack.

'From the information I have received [automatism] is the only conclusion I can come to unless she ... was faking this condition,' Dr Yuen said, adding Zheng would need to have a very good knowledge of the condition to fake it convincingly.

The doctor noted Zheng had experienced episodes of sleepwalking when she was a child. He had also not completely eliminated an epileptic seizure as a possible cause of her apparent automatism, although aside from Zheng reporting a strange smell just before her blackout, there was scant evidence to suggest that was what lay at the root of the problem.

Peter Yu Wai-tak, a former government forensic psychiatrist, agreed with Dr Yuen's conclusions.

'I believe Zheng is telling the truth,' Dr Yu said. 'The only conclusion is that ... the acts were without conscious control.'

The obvious confusion experienced by Zheng immediately after the attack was typical of someone waking from a sleepwalking state.

In his opinion, her actions - she had called 999 to report that she and Ms Yang had been attacked and had not embellished her story at all - tended to verify her story. Cases of people becoming violent when sleepwalking were very rare but not unknown to medical science, he said.

It was put to Dr Yu by prosecutor Frederic Whitehouse that sleepwalking normally occurred when people were actually asleep.

Dr Yu replied: 'I suspect she dozed off very quickly, in a matter of seconds, while still standing and went into a state of sleepwalking. People can doze off while standing.'

Mr Whitehouse then asked why Zheng did not wake up during what was a very violent and prolonged struggle with Ms Yang. Dr Yu told the court it was his belief that Zheng was acting out a violent dream.

The trial continues today before Mr Justice Michael McMahon.