These are tremendously powerful photos of the Tehran riots.
Update: Commenter Roozbeh suggests that the protester is not, in fact, lending aid, but “taking” the officer, and points to another photo of the same scene. In this third photo, it appears that two protesters are leading the police officer out of the crowd.
There are plenty of fairly brutal photos in that same series — many cops have responded to the protests violently, to be sure, and that’s really important to recognize. Aside from awareness of the apparently stolen election that has mobilized protesters to the streets, I of course don’t know what’s in this particular protester’s mind, but it doesn’t appear to me in either photo that he’s trying to hurt the police officer. The only thing that would resolve that would be to find him and get his description of the scene — I hope that somebody does.