In Sleeping Dogs for the PS3 and Xbox 360, you can disarm enemies and jack their weapons for your own.
To disarm an armed enemy, walk up to them and double tap B on Xbox 360, or double tap Circle on the PS3.
For better results, give them a kick or punch to the gut to stun them first.
If you’re looking for your first gun, try to disarm a cop walking around the city.
