Given that 99% of the crimes are committed by repeat offenders, a simple dusting for fingerprints (costs pennies) could likely identify the culprit. But they don't bother. And they act like we've seen too many movies/tv shows. But when an "interesting" crime happens they do in fact dust for fingerprints (cheap!) and do all sorts of swabbing and testing (expensive). The police are lazy in CA especially. And yet they are also extremely well paid in CA. Someday, hopefully, this will change.
If a cop is making $30/hr, and we allow "pennies" to be as much as $0.25, they would have to complete the entire dusting for fingerprints process in 30 seconds.
Remember the DA is part of the equation. For low priority crime, there’s a lot of risk with using fingerprints. They won’t take a case they may not win.