'Murder' only requires a single bullet.
In the fallout over Lee Clegg in NI, a military legal advisor gave a presentation in which he confirmed that 'homicide' does not exist in UK Law and that the operator was responsible for every bullet including a ricochet. This when SH were armed with GPMG, an Area Suppression weapon.
This makes urban warfare such as seen recently in A Kenya shopping centre an invitation to go to jail without passing go or collecting £200. Yet Nations of the world will have seen this happen and prepare for repetition.
The means to challenge these cases, be it Police or Military should be supported by those who task them. There is no way that any weapon from an aircraft can be used with the finite precision that the Law would like to believe is possible.