A DISTRICT Court judge yesterday told the father of a defendant who had attacked five boys to instil in his son some sense of decency towards people. Judge Chua gave the advice to the father of Chan Kin-ling, after she sentenced the defendant to three years and eight months in jail. Chan was found guilty after trial of five counts of wounding. The incidents occurred on April 14, 1991. ''You should try to instil in your son some sense of decency and care for other human beings. You can't go and chop people just for a look you did not like,'' Judge Chua said. She said the defendant, now 21, already had serious convictions for theft and possession of marijuana. A background report stated that he was totally unrepentant, she added. In sentencing, Judge Chua said Chan, the only son of a hard-working couple, was rebellious and had associated with Wo Shing Wo triad members. She said Chan committed the offences a day before his 19th birthday. Defence counsel Anthony Yuen asked the court to impose the shortest term of imprisonment on his client. The Crown said Chan and others attacked five victims at a Mongkok amusement centre after a group of boys allegedly looked at Chan and his girlfriend.