The guy that was killed at the petrol station was himself a "
44-year-old drug gang leader and loan shark", not exactly a saint with beneficial contributions to society. Malaysian police (with help from Singapore police) have arrested 4 young women and 9 young men, obviously from a rival gang or associated gang (Malaysian police say they're still working on 3 theories : territorial dispute, drugs payment dispute, or assassination) and yet the killed gang leader's own gang members (also drug dealers and loan sharks) go scot-free, just because they're not involved in this particular case of his murder.
https://sg.news.yahoo.com/arrests-johor-cops-home-main-murder-suspect-235400065.html