Randomize names for NPCs only once?

I have a bunch of names and surnames and I want an NPC to choose one name and one surname randomly (names and surnames are independent enums).

But I want that to happen once only in the whole game. If the NPC despawns, I want it to retain that random name the next time that he spawns.

I know I could do something like this in the construction script. My question is if the NPC would have the same name every time he spawns again or would it be randomized again.

This would not happen at runtime (no change of names), only one time when the game begins (or in Editor, however you want to call it).