J'datharr is a Khajiit assassin waiting outside of Windhelm, behind the stables. He is sent by the Thalmor to kill Malborn after the completion of the quest "Diplomatic Immunity," before he can flee Skyrim. He carries a note addressed to him. Since he is not part of a Khajiit caravan, killing J'datharr will incur no bounty, even if witnessed by the other Khajiit. Hold Guards will not react to any assault towards him either, and may actually help in killing him.