Even if you have hard evidence they'll often refuse to do anything.

One of my relatives had her car stolen and the cops told her they would almost certainly not find it until it was abandoned (not sure why it's so hard to keep an eye out for "model X in color Y with no tags and/or 123ABC tags") and when it was abandoned and they brought it back it was full of personal effects (skateboarding stuff and clothes mostly) including a bunch of court documents, with names on them, for the same dude.

When she told the cops about this and pointed to his public facebook profile which was mostly about skateboarding, they told her that all of that stuff could have been stolen too so it was impossible to investigate based on the effects left in the car.

American cops don't solve crimes they just protect rich people's property and shoot innocent people.