A variant, called Home Invasion Robbery, occurs when the robber follows the victim home, knocks on the door to gain entry, or lies in wait after a break-in. This simply requires use or threat of force. It's synonymous with the term blackmail. It's the unlawful taking of property from another by threats of future harm. The element of time is what distinguishes extortion from robbery.
Extortion is the threat of some future harm rather than immediate harm.
There's also no need for victim and offender to confront one another. As a general intent crime, the motives for it don't really matter. Extortion is the most common criminal charge against corrupt police officers. Criminal Law .