The head of state/government must be actively serving their term (retired officials don’t count, nor do those who are elected but have not started their terms in office)

To clarify on the wording of the question: refers to a head of state/government serving for a country in the specified continent

The assassination does not need to take place in the continent, the only thing that matters is the continent that the country of the assassinated official is in

Assassination refers to the targeted purposeful killing of the official, ie accidents/ambiguous events and deaths in war will not be considered

Borders: for the purposes of this question Turkey is in Asia and Russia is in Europe

Countries: all UN member states as well as observer states (currently Palestine and The Holy See (aka Vatican City). Once Bougainville gains independence they will be included. I will also include countries that are recognised by more than 10 countries so Kosovo, Taiwan and Western Sahara. But not currently Abkhazia and South Ossetia

Future countries established on earth or other bodies will be included if they gain the recognition of at least 10 other countries (potential candidates: Catalonia, Scotland, an Antarctic territory, Martian territory etc)

If you have any insider info feel free to share ;)