Three teenage girls were placed on probation after they admitted kicking, punching and spitting on a schoolmate in February and burning her hand with a lit cigarette for allegedly bad-mouthing one of the trio. Their "triad-like" humiliation of the victim, 15, drew criticism from acting Chief Magistrate Andrew Ma Hon-cheung at the sentencing yesterday. Shum Sin-wa, 16, would undergo one year of probation for two counts of assault occasioning actual bodily harm, Ma ordered in Sha Tin Court. The other two defendants, who cannot be named because they are 15 years old, will answer to a probation officer for the next 11/2 years over two counts of the same offence and one count of robbery. Their cases were dealt with at the Juvenile Court. A fourth accomplice, Lau Tsz-kwai, 16, also pleaded guilty to one count of assault occasioning actual bodily harm. She was remanded in custody - which Ma said would give her a chance to reflect on her actions - and would be sentenced on January 20. Ma said Shum was the instigator as the victim had allegedly spoken ill of her. "If you wanted to confirm if she had bad-mouthed you, you could have launched a complaint or confronted her with it," the magistrate said. The court heard that on February 20, the four ganged up on the victim at a rear staircase of the Mei Lam Shopping Centre in Sha Tin. "[They] punched and kicked [her] abdomen and back," a court interpreter said, reading out the brief facts of the case. They also carried out demeaning acts such as spitting on the girl's hand and demanding that she wipe the saliva over her face. One of the 15-year-olds pressed a lit cigarette butt on the victim's right palm and bit her left forearm, while the other 15-year-old ordered the victim to burn her hands with the cigarette herself, which she did, the court heard. They also robbed her of HK$150.