Does patrolling the area prevent 13-year-olds from being shot and killed?

This sounds like a silly question, because it's so ingrained in how we think about policing and crime, but I think it's a question we have to reassess when crime is low. If an area is entirely lawless - in such a state of societal collapse that everyone is allying with a local gang for their protection - then having police patrol the area is likely useful in the same way as sending UN peacekeepers to areas controlled by warring armies or sending knights to clear out dangerous medieval roads. But most places in the world these days have functioning governments.

A news report about the shooting (https://www.usnews.com/news/us/articles/2021-11-03/indiana-m...) says:

> One of the trick-or-treaters told police that he exchanged words with a man about 30 to 45 minutes before the shooting, which happened around 7:30 p.m. The man threatened to get a gun and shoot them, according to court documents.

> The group later saw a car with five or six people inside who appeared to be staring at them. The man who had exchanged words with one of the youths got out of the car with some of the other occupants. Another man took a “shooting stance” and shots were fired at the trick-or-treaters, court records said.

> A police officer captured Crews after the father of one of the youths chased him in the neighborhood, according to court records.

It's pretty clear that, even if this is a more dangerous area than some posh suburb of Chicago, it's still relatively safe, since not only were there kids out trick-or-treating by themselves, they felt comfortable getting in a verbal argument with someone who threatened to shoot them and they stuck around the area for 30-45 minutes. You don't do that in an area where shootings are particularly commonplace.

So, suppose that the police were patrolling the area. What would have been different? The man was caught - did he genuinely expect not to be caught, and would increasing police presence have dissuaded him? He also, apparently, got out of the car and started shooting - would there have been enough time for a police officer to react and save the child's life?

Meanwhile, the article talks about how "predictive policing" focuses on crimes that are not murder:

> Searching for a robbery suspect described only as a Black man between the ages of 16 and 18, officers stopped 161 people and arrested 10 at the intersection where the store was located in a span of two weeks. [...]

> Some encounters turned deadly. In 2016, LAPD shot and killed 31-year-old Keith Bursey Jr at the intersection, after the car Bursey was a passenger in was stopped by gang enforcement police investigating “an odor of marijuana”.

If a police patrol in Indiana had stopped and searched every car on Halloween with "an odor of marijuana," would they have found the car with the armed man and saved this teenager's life? If they had done a dragnet search for a teenager who stole some clothing, would they have made the area safer?

The problem (and I'm not saying I have an easy solution!) is that overpolicing doesn't particularly contribute to lowering crime rates, past a certain point. If you're trying to prevent a genocide in occupied Srebrenica, by all means, send in armed patrols and authorize them to use their arms. If you're trying to prevent some ten murders a year, all of which have unrelated causes, though? It's very much the "Something must be done, this is something, so this must be done" sort of reasoning.

And that doesn't even get into the fact that overpolicing can make the area even more dangerous by fostering a distrust of police - if you were a teenager in a bad part of town and the news liked to call you and your friends "youths," and you got in an argument with someone who threatened to shoot you, would you feel comfortable telling the local police patrol?