Now, the police officer who had arrested Mernel Koh, 15, is blaming himself for her death in his personal blog.

The officer, who did not name or identify himself in the blog, wrote about his regret over the whole incident. He was the one who arrested Mernel, a Secondary 2 student at Fairfield Methodist Secondary School, when he found her sleeping at the void deck of a block of flats in Bukit Batok.

Checking her identity card, the officer realised she was wanted for a case of shoplifting and took her back to the police station.

Mernel was supposed to attend court to be charged with the offence on the day she was found dead together with an older male friend at the foot of a block in Bukit Batok West Avenue 6.

Giving a rare insight into the psychological impact of what policemen face in the line of duty, the officer wrote: 'I am a murderer. If only I did not screen her on that day, she might not (have to) turn up in court on 30th Sept and tragic might took a step backward (sic).'

He also said that he never expected the girl to have committed the 'silly act'.

'She was quiet while I was bringing her back to the station. Never did I think that the next astonishing thing would happen (sic),' he wrote.

The blog, which was accessible by the public, has now been restricted to only those who have been granted access by the blogger.

When contacted, a police spokesman confirmed that the blogger was one of its officers and said arrangements had been made to provide him with counselling.

'There are existing guidelines on blogs by police officers and we are checking if he committed a breach of these guidelines,' the spokesman said.

Other agencies, such as the Defence Ministry, have strict guidelines on blogging.

In 2005, three operationally ready NSmen were asked by Mindef to take down online postings about a recent military training stint in Australia, over fears of a security breach.

Police are investigating the circumstances behind Mernel's death. A plastic bag containing a can of industrial glue was found on a wooden stool at a staircase landing of the block the pair had fallen from.

CHONG CHEE KIN