A POLICE constable and a hawker charged with plotting to pervert the course of justice will face trial in the High Court. Police officer Hau Wing-sum, 25, and hawker Chu Kam-to, 43, appeared before Magistrate Judianna Barnes in the Eastern Court yesterday and were committed for trial. Hau faces a second charge of stealing an exhibit bag containing 191.3 kilograms of heroin from Sheung Shui police station on September 29, last year. Chu and his wife, Hong Yuk-lan, 34, were released from custody after the drugs went missing. They had faced charges of possessing a dangerous drug for the purposes of trafficking. No trial date was set.