1. It's not a priority area to be fixed. (Police aren't doing much to address the crimes that have been commited)
2. The police aren't getting a lot of cooperation from witnesses ("don't snitch" which benefits gangs and gang retailiation.. again supporting the cycle of crime)
3. Is it the police are being held back from the region (that would be a corruption issue)
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Anyways, police can fix the problem behavior instantly. Murders don't view their behavior as concerning. They tend not to have a lot of things stopping them on lessor crimes either. Programs take years to be fully affective. (If not decades)