A Neutral Model of Gang Territory Formation"

Many criminal street gangs are territorial in nature claiming compact geographic regions as their home turf. Gangs defend their territories both with the threat and use of violence. A neutral model based on spatial Lotka-Volterra competition equations shows that territories are strictly stable only where gangs are exactly symmetrical in all characteristics, which we interpret as a neutral condition. We test the model against data on violent crime involving thirteen street gangs in a region of Los Angeles. We find excellent agreement between model predictions and the observed spatial distribution of crime.