Brower park violence

Yesterday our babysitter had my 2 year old at the Brower Park playground, where we go regularly. Around 4 PM a young boy (12 or so) was beaten badly by a group of older young men (early 20s). Apparently, the boy was laying in a pool of blood, and was dragged away by a couple friends. My babysitter said she and other adults there were screaming and crying for the assailants to stop (they didn't), and called the police, who came about 15 minutes later. I called the 77th precinct yesterday and spoke to someone in community affairs, who promised he would, "call me right back" with more information. I still haven't heard from him 24 hours later. It's amazing how millions can be spent on the Children's Museum (around next to the playground) yet there is rarely a noticeable police presence around the park, nor park employees there regularly during daylight hours (from what I've seen).