The gold standard are surveys that just ask people "have you been the victim of the following crimes." This does not rely on police at all. This does not rely on a fuzzy definition of violent crime. People are not motivated to over or underreport things.

We can further cross check this data against things like insurance reports, since people tend to report things like vehicle theft.

People, when asked, report being victims of crime far less today than they did in the 90s.