A decision by prosecutors to synchronise actions against an Occupy protester charged with assaulting police and seven officers who allegedly beat him up means the order of their trials could affect witness credibility, lawyers said yesterday. A complicating element in the legal drama is the dual identity of Ken Tsang Kin-chiu, who is in one case a victim and potential prosecution witness while in the other a defendant. He is due to appear in Eastern Court on Monday, the same day the seven policemen are due to appear in the same court, in a move justice officials insist will ensure "fairness". Yesterday Tsang and his lawyers spent two hours inside police headquarters in Wan Chai but later declined to comment on the reason they were there. Tsang's case will be handled by magistrates while the officers' case will be taken up at a higher level in the District Court. READ MORE: Occupy protester Ken Tsang faces charges of assaulting Hong Kong police Cases can proceed faster before magistrates than in the District Court, and timing could bear on the outcome of each case because the credibility of witnesses could be put into doubt. "If a defendant was convicted and had a criminal record, it might affect the judge's impression on the credibility of his evidence in another case," said Jeffrey Tam Chun-kit, a barrister who has handled criminal cases arising from protests. University of Hong Kong legal scholar Professor Simon Young said the result of one case could offer reference for the other. "At some point, the courts will need to address the order of trials. I would think that those advising Mr Tsang would want to see the trial of the seven officers handled first," Young said. "If there are convictions, it will provide the factual basis for pre-trial motions ahead of Tsang's trial. In particular, there will be a basis to argue for a stay of Tsang's proceedings on grounds of police brutality." Fellow HKU legal scholar Eric Cheung Tat-ming said the Department of Justice's statement on Thursday did not say whether any of the seven officers was involved in four further charges against Tsang of resisting arrest. If they were, they could appear in his case as witnesses. But Cheung said courts would take into account other factors when determining trial dates. On the scheduling issue, Secretary for Justice Rimsky Yuen Kwok-keung said: "The legal representatives [of Tsang and the seven police officers] can advise the judges as to which prosecution is to be handled first. "This is most fair to ... both parties," he added. Yuen reiterated that the two cases were not bundled due to politics: "Any suggestion that the prosecution of Mr Tsang is to blacken his character or his reputation is absolutely groundless." Prosecutors charged seven officers with one joint count of causing grievous bodily harm with intent. They are Chief Inspector Wong Cho-sing, Senior Inspector Lau Cheuk-ngai, Detective Sergeant Pak Wing-bun, and constables Lau Hing-pui, Chan Siu-tan, Kwan Ka-ho and Wong Wai-ho. The maximum penalty is life imprisonment, though the District Court's powers are limited to a seven-year sentence. Chan faces a further charge of common assault.