The mainland gangster who laughed in a television interview as he described a gun battle with police during a dramatic armed robbery is an ex-soldier, it emerged yesterday. Ma Shangzhong stole the show from alleged crime kingpin Cheung Tze-keung last week when Guangdong TV news programme Society Focus ran an interview with him. 'The way he shot was professional. He had received army training,' a source said. Ma is alleged to have taken part in five Hong Kong jewellery shop robberies in 1991 with convicted gunman Yip Kai-foon and others. Ma was one of two armed robbers in the raids who were unmasked. The gang netted $5.7 million in jewellery. He was also accused of complicity, along with Yip, in the murder of Hong Kong resident and police informer Choi Chi-hung in Shenzhen on November 27, 1995. During the televised interview, Ma smoked and laughed as he described how the gun battle had attracted many onlookers who thought the gang was shooting a film.