In October 1984, when he was 23, Yip led a gang of five armed mainland Chinese men into Hong Kong.

[citation needed] On 28 December 1984, the police carried out a sting operation involving an undercover policeman posed as a potential buyer for the stolen goods.

[3] Yip contested the conviction, claiming that he was asked only to find a buyer for what he thought were sub-standard watches produced in local factories; his appeal was dismissed in 1987.

On 9 June 1991, he and his gang, armed with AK-47s and pistols, robbed five goldsmiths shops on the "Golden" Mut Wah Street in Kwun Tong.

[6][8] Yip is thought to have been involved in a 6 January 1993 jewellery store robbery on Nathan Road in Mong Kok, when a gang fired 30 rounds from AK-47s, killing a woman passerby.

[8] Macau police suspected Yip was involved in an April 1994 armed heist of HK$40 million in gambling chips from the casino at the Hyatt Regency Hotel on Taipa.

His career finally came to an end on 13 May 1996 when he was arrested following a Kennedy Town gunfight with police that left him paralyzed from the waist down.

[13] He was charged with possession of firearms and ammunition without a licence, and shooting with intent to do grievous bodily harm, stemming from wounds one of the officers received in the course of the arrest.

[18] He dismissed his defence team two days later, subsequently appearing to fall asleep when given the chance to cross-examine a prosecution witness.

[27][28] Yip continued to maintain his innocence over the 1996 shootout, offering a substantial reward for a witness who he alleges saw the events leading up to his arrest.

[4] On 11 January 2010, Yip was sentenced to an additional six months in jail for assaulting an officer at Stanley Prison on 30 April 2009.