The person who threw a bottle of acid into Apliu Street in Sham Shui Po on Sunday did so less than 15 minutes after officers left their observation posts on the rooftops of nearby buildings, a police officer said yesterday.
'It is possible that the perpetrator reconnoitred the area before the attack was launched or the person is a resident in the area and knows when our officers end their surveillance each day,' the officer said.
Police have been manning observation posts on rooftops, and uniformed and plainclothes officers stepped up street patrols, after three acid attacks in the district last year.
Chief Inspector Wallace Lee Che-hung of the Sham Shui Po district crime squad said it was possible Sunday's attacker was the same person responsible for the three previous attacks in June and October.
'But we do not rule out the possibility that the latest attack was a copycat [crime],' he said.
Lee said investigation showed the attack was launched from the roof of a block of flats at 212 Apliu St.
'The front door of the building is unlocked, and people are free to enter and go to the roof. And there is no surveillance system in the building,' he said. Police believe the lax security was the reason the attacker chose the building.
