If they don't do their job and you have proof then they're screwed

Nope, Warren v. District of Columbia had the SCOTUS rule that the police have no obligation to protect or serve. They can’t be sued for failing/refusing to do their job, even if it puts people in harm’s way.

The case revolved around a dude on a train who got stabbed. There was a psycho moving down the train cars stabbing people, and the police were chasing him. A passenger saw the attacker coming, saw the police in pursuit, and decided to help. He stopped the stabber, expecting the police to quickly catch up. Instead, the police locked the passenger inside the train car with the stabber, and watched through the tiny windows until the stabber was tired out from stabbing the passenger.

The passenger sued the police department, stating that they refused to protect him. The SCOTUS ruled that the police have no obligation to protect nor serve, and can’t be sued for failing to help you.