The Chinese Secret Police (CSP) aren't the types to hand out speeding tickets or bust people for underage drinking - they are a paramilitary force trained to use lethal force without hesitation. Officers of the CSP are the finest operatives the People's Republic of China can field, and are often used as the shock troops and Rapid Reaction Units. CSP officers are experts in lightning raids - when apprehending suspects, they make liberal use of flashbangs to stun and disorient targets and innocents alike, and follow up with a hail of gunfire or close combat takedowns.
Part of every CSP officer's training is exposure to the weapons they use for crowd control: namely flashbangs. While they aren't truly immune to these weapons, they are unlikely to be put down for long by any sort of riot control weaponry.
The highest ranking CSP veterans are trained to as marksmen. Familiar with all manner of rifles, these agents cover their squad from afar. Triad members that often run afoul of the CSP take every opportunity they can to set up ambushes if they know their patrol routes - they place traps, then seek cover and wait for the traps to be sprung.