South Simcoe police say they have arrested a 14-year-old after an investigation into a “targeted and disturbing” assault on a person with a disability.Police say over the past several weeks they have been investigating a series of incidents posted on social media platforms, including Snapchat, that showed the victim from the town of Bradford West Gwillimbury being harassed and bullied by a group of youths.Police say the investigation intensified after a video was circulated online showing the victim being led into a secluded area where they were repeatedly and violently assaulted.Police say a 14-year-old from York Region turned themselves in on Tuesday and they have been charged with multiple counts of assault.Police say the investigation into the incidents is ongoing and additional arrests may follow.Police are urging parents and guardians to speak to their children about responsible social media use and the serious consequences that can result from violent and bullying behaviour.