Do armed residents engaging in self-defense count as civilians during armed conflict?

Question

• Resident T does not hold any official position in an armed group
• An Army or a militia from a foreign country not recognized by T's country, enters T's neighborhood.
• T attempts to defend his neighborhood and is subsequently killed.

Was T a civilian victim?

If no, does the mere fact of being clearly armed loses him that status? or does he have to shoot back?

Answer 1

T became a combatant by spontaneously picking up arms

For simplicity, I will call T Ted from now on.

Assuming that the assailants of the armed forces were following the rules of law, Ted became a lawful combatant who would be protected as a PoW if captured by picking up arms openly and engaging in hostilities with them. That is regulated in Art. 4 A (6), the Third Geneva Convention (Geneva III).

Article 4 - Prisoners of war A. Prisoners of war, in the sense of the present Convention, are persons belonging to one of the following categories, who have fallen into the power of the enemy:

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(6) Inhabitants of a non-occupied territory, who on the approach of the enemy spontaneously take up arms to resist the invading forces, without having had time to form themselves into regular armed units, provided they carry arms openly and respect the laws and customs of war.

Because he had no time to join a militia or volunteer corps (Art 4A(1&2)) and get a uniform or distinguishing mark, he is not one of those. But he was picking up arms spontaneously and became a lawful combatant under Art.4 A(6) of Geneva III. As long as he carried his arms openly, he was allowed to fight as he was, and would be required to be given PoW status. However, as Ted fell he stayed a combatant, even in death. This is verified in the Additional Protocol I to the Geneva convention, Art. 50:

Article 50 - Definition of civilians and civilian population

1. A civilian is any person who does not belong to one of the categories of persons referred to in Article 4 A (1), (2), (3) and (6) of the Third Convention and in Article 43 of this Protocol. In case of doubt whether a person is a civilian, that person shall be considered to be a civilian.

Because he picked up arms spontaneously and resisted under Art.4(6), he is not considered a civilian but a combatant under the rules of war. As such, the fact that Ted died does not become murder or manslaughter but he is a fallen (legal) combatant.

Answer 2

T is an enemy combatant.

According to the Practical Guide to Humanitarian Law, civilians who directly participate in hostilities temporarily lose their protection. This means that they can be lawfully attacked during this period.