There is no alternative to a police force, except for putting the military in the streets.
It doesn't matter whether it's a communist nation, a theocratic nation, a military junta, an oligarchy, or a monarchy. They all have police forces, and all of their police have elements that are armed and use them when encountering dangerous individuals or groups.
There are a "few" small nations without actual armies, but there are always units that enforce a nation's laws.
As statistics have shown, there are actually very few unarmed individuals killed by police in the US. It happens, but it's not rampant. A study found that even the police acknowledge that they are rougher with blacks than other groups, but that shootings are not disproportionate because of race. Their reasoning for why they are rougher on blacks than other groups is because when having to stop a black person, the individual will become agitated and act out against the police just trying to do their job. If you speed, they will give you a ticket. If you don't stop at a stop sign or light, they will give you a ticket. If have a taillight or headlight out, they will give you a warning ticket. If you have an expired license plate or no drivers license, you will be ticketed. I see video after video after video of blacks being pulled over for an offense and asked to produce their driver's license, only to be told that they didn't have one, or it's at home. You are NOT supposed to be driving on the streets or roads without an actual up to date driver's license on your person. Many times the person will drive off and have to be chased down, stopped, dragged out of their car and the driver's excuse is: I was scared. Just cooperate.