Double Tap

Leslie Cheung plays Rick Pang, an IPSC champion who is also a gun expert who tinkers with his pistols and modified its magazine to perfect his technique known as ‘double tap’ which is the terminology where a shooter can place two exact shots in the same spot to maximize marksmanship in any competition.

In one of the shooting competitions, he goes up against another experienced top cop who is just as comfortable on the pistols as Rick, named Miu. Unfortunately, the competition was marred by a depressed day trader who threatened the safety of the contest so badly that Rick was forced to kill him with his trademark double tap as the former approaches Colleen and Vincent (as the trader was armed). Miu took note of this astounding technique in the post-mortem while Rick’s experience from this encounter was strangely exciting to him and he discovers his lust for murdering others in cold blood. —Wikipedia