An ex-convict was yesterday jailed for 10 years for killing his girlfriend's 8-month-old baby, while the girlfriend - now five months pregnant by another man - will go to prison for three years for wilfully ill-treating her son. Deputy High Court Judge Judianna Barnes Wai-ling sentenced Kow Chi-ming, 35, to 10 years' jail for killing his live-in girlfriend's son, Ng Tsz-kin, in June 2003, when the baby boy was left in his care while his mother worked in a Mongkok karaoke bar. He suffered 30 injuries in the two weeks before his death on June 20, 2003. In sentencing, Judge Barnes said: 'The baby died as a result of deliberate abuse he suffered at the hands of Kow.' She said he was responsible for the baby's fatal injuries - a head injury and brain haemorrhage. The judge said a psychological report concluded that Kow, who was unemployed, displayed several psychopathic traits and had a long history of violence. The same report observed that he showed little remorse over the death. 'Even assuming the baby was indeed crying a lot and Kow's patience was put to the test, it is still difficult to understand how Kow, a grown man, could inflict the kind of injuries ... to a defenceless and helpless baby,' she said. 'It was no excuse [for Kow] to vent his anger, frustration or feelings of inadequacy on this baby.' Ng Bik-fung, 27, was jailed for three years for ill-treating and neglecting her son. Judge Barnes said Ng failed miserably as a mother. 'She should have provided, at the very least, basic care if not love ... for her own flesh and blood,' Judge Barnes said. 'It is extremely hard for any normal human being to understand how Ng could have neglected her baby so wilfully.' She noted that a psychological report concluded Ng had shown little distress or grief when her son's death was mentioned. With Ng's new baby due in September and after she gave up her first-born son in 1999, Judge Barnes said 'one can only hope she can take better care of her new baby'. Kow, who had 17 previous convictions, was found guilty of one count of manslaughter last month in the Court of First Instance. Ng was convicted of one count of ill-treatment or neglect of a child or young person under her care.