So this heavily implies that he knew what he was doing, he most likely knew it was wrong, but still did it.
With this in mind, no, I would not forgive him.
Such actions like this are the actions of people who may or may not go a step further and harm a human. That's how a lot of serial killers start out. Maybe this person does repent and knows he was fucked up for doing it. And maybe he is sorry and would never do something like this again.
I will definitely acknowledge his apology as sincere, but I will not forgive him. I would actually probably be cautious of him, if not fear him.
This action is not akin to a "mistake as a child". Behavior like this would make me wary of him as a person and actually question if I am safe around him.
Also: Just because someone apologizes and repents for their behavior doesn't mean they are entitled to forgiveness, especially if they do something like this or a step further. People have the right to not forgive just as much as they have the right to forgive. So this guy can ask for forgiveness all he wants -- it's not up to him. It's up to the people he's asking. Some will forgive him. Others will not.
I am an "other".
Of course, the people who harass and abuse him are no better because they are wasting their own time and life and energy doing these things, and they're becoming the very thing they're "so-called against". You don't continue to harass when the elephant in the room has been addressed. You acknowledge what happen, you hope for a justified punishment, and you keep walking (avoiding people like that). In all honesty, people who continue to harass after a justified punishment has been made make me question if they get off to just being that way.
If I saw this guy, I would be walking on the other side of the street. Because even if he is sorry and does feel horrible and would never do that again, he has created this thought in my mind that I need to keep away so that I am safe.
My supposed fear of him would be the product of what he did.