In Korea, policemen are upstanding citizens who put their lives on the line to serve and protect and keep law and order. Role models for the rest of the community, these cops are true heroes.

Detective Kang (Sol Kyung-gu) isn't one of them.

A walking time bomb with a badge, Kang's as likely to be taking backhanders from criminals as banging them up.

When he becomes the only witness to a double homicide, Kang goes after the chief suspect, rich city boy Jo (Lee Sung-jae), with every dirty trick in the unofficial handbook - claiming that sometimes you've got to trample over the rules in order to enforce them.

Taking its cue from the "Dirty Harry" school of police procedure, this Korean thriller is an offbeat mix of violent thrills and slapstick laughs from director Kang Woo-suk (widely regarded in his home country for the "Two Cops" action comedies).

Working better as a comedy than a thriller (there's a hilarious scene where Kang tries to fit up a villain on a breaking and entering charge by planting a screwdriver on him), "Public Enemy" has some enjoyable slapstick moments, all of which are played to the hilt by Sol Kyung-gu, an actor with a remarkable ability to morph his face from hangdog sadness to gormless stupidity and explosions of pent up rage in the space of a single beat. Although well supported by Kang Shin-il as his foul-mouthed police captain and several comedians in funny minor roles, Sol steals the movie.

As a thriller, things are less interesting. Making heavy weather of the class-based jealousies between Kang and Jo, "Public Enemy" never manages to build much suspense.

Director Kang says he wanted to make a serious point about vigilante violence, police work and maintaining law and order. Something must have been lost in translation.

In Korean with English subtitles.