A day after her son was found responsible for killing two fellow policemen and a security guard, Cheung Wai-mei has spoken of the difficult time she and her family have gone through as relatives of the perpetrator of Hong Kong's most high-profile shoot-out. Speaking exclusively to the South China Morning Post, Ms Cheung dodged the question of whether she, as the mother of constable Tsui Po-ko, should apologise on behalf of her son. The 61-year-old retiree said she had tried to talk herself into acknowledging that her son was a killer, but she still found it hard to reconcile the image of Tsui as a brutal gunman with her memories of a good, and at times lonely, son. Asked to respond to the calls for her to apologise, Ms Cheung said: 'Only those who have ever lost their loved ones would understand our feelings. Nothing could ever compensate for the loss. 'I sincerely wish everyone who suffered a loss of loved ones could regain their strength to carry on with their lives. I send this as my best wish to everyone of us involved in the inquest.' Ms Cheung was the highest-profile member of the Tsui family during the 37-day inquest, maintaining a dignified presence during her regular appearances at the court. Acting as a shield for her daughter-in-law and granddaughter by facing the media barrage outside the court, she faced harsh questions inside the court, about whether her separation from her husband, due to her involvement in another relationship, had affected her son's character. 'I heard witnesses saying in the inquest that my son could have suffered a lot of influences from my separation with his father. I ask myself whether I affected my son so badly. It makes me blame myself at times. That was really painful.'