86fb992a_Grand_Theft_Wiki__the_GTA_wiki__Reward_for_sparing
[Mission] Late Checkout [Target] Diamond dealer [Description] The first diamond dealer to kill (he looks like a rabbi) is in the kitchen. If you kill everyone in the floor and in the kitchen but him and you get close to him, he will drop his weapon and raise his hands. Niko can shoot him to kill him or just walk away to spare him. This doesn't have any repercutions later in the game and is probably just a way to add a special touch to the mission. [Reward for sparing] 
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R a n d o m e n c o u n t e r
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Choices in GTA IV - Grand Theft Wiki, the GTA wiki