Three police officers knocked on the apartment door of a 15-year-old boy. He had already been on both sides of a police blotter: shot and stabbed, but also arrested on robbery charges. He ran in an East Harlem gang and lived with his grandmother on the seventh floor of a public housing building, where the stairwells reeked of marijuana.
Read more in The New York Times: http://www.nytimes.com/2013/03/04/nyregion/to-stem-juvenile-robberies-police-trail-youths-before-the-crime.html?hp