If a normal boy is part of a toxic peer group led by a sociopath he can be led into behaviors that he'd otherwise know better--not an excuse. The sociopath can have immense mind control, gas lighting, brain washing powers that can convince weaker minds, especially young people, the rightness of their toxic behaviors. A good example of how this is often done, is the scene in Glenngary Glennross where one salesman convinces another into robbing the office. Add to it the pleasure of sex and the confusion of a young developing mind and you have a recipe to turn any normal boy into a rapist.

Again this is no excuse. The boy should be prosecuted to full extent. They need to be taught how to stand by their own values; and gain the internal self esteem needed so they can easily recognize toxic groups and stay away from them.