Report function?

[Slim Pickens]

Newb here. I've recently started playing online. I played story to completion a few years ago, but never ventured online until now.  I have many years experience on GTAO, so I'm no stranger to the concept of griefers.   I know how to deal, but I'm just so freaking tired of it.  'durr-hurr I done shot an unarmed and non combative person in the head ... Durr-hurr.  Doesn't it ever get old? 

How is there no report function in this game?  GTA has it, not that I put any faith in it. 

Rockstar really aim for the lowest common denominator with their game mechanics.