Once used to describe an action of firing twice quickly in succession with a pistol, the definition of Double Tapping in 2012 has been redefined as the act of assassinating or murdering someone, or a group of people, and then waiting around until people come to the rescue, or start examining the aftermath. As the rescuers, compatriots of the dead, or onlookers gather round, the killers then hit them with another whammy and pow; the killer scores twice the kill. (Experience points are earned and the killers potentially go up a level)
Another way of achieving a double tap is to wait for the funeral of the dead of the first strike. Then while family, friends, associates and onlookers are gathered around in their suits mourning the deceased...BLAM! Hit the lot of them!
Apparently the term Double Tap originated from intelligence agents describing what some terrorist groups have been known to do including Hamas. The mafia, however, strictly forbids it under any circumstance. i.e. it is strictly forbidden to go and blast the fuck out of mourning women, children, grandmothers, aunties etc.
Unfortunately this definition of Double Tapping is making worldwide news because there have been an escalating amount of incidents this year where this controversial form of mass killing is being regularly played out, in fact it appears to be now seen as an effective strategy by the US military and intelligence agencies.