RPGMemes

For example, what if the person casting the spell had a hair sample, or a severed finger or some other item from the monarch's body,

RAW and RAI that wouldn't work, otherwise you could cast Inflict Wounds on someone by merely having a strand of hair from them. The RAW answer would be to have someone cast Contingency + Gentle Repose, though at that point you may as well add in a teleport or something instead