That's a multi faceted problem. Murder rates also were halves since the 80s in the US, it's not necessarily the same type of criminality
In other countries the clearance rates are as high as ever. The US is an exception in many aspects in the West, closer to third world countries depending on what metric you look at
> overall, findings showed that the clearance rate in Finland and Switzerland in the years of analysis was very high, in some years of the analysis even reaching 100 percent. Internationally, these rates are extraordinary high, even in comparison with other European countries such as Italy (67 percent and, later, 78 percent) , Estonia (80 percent), England & Wales (85 percent) and France (80 percent)
In other countries the clearance rates are as high as ever. The US is an exception in many aspects in the West, closer to third world countries depending on what metric you look at
> overall, findings showed that the clearance rate in Finland and Switzerland in the years of analysis was very high, in some years of the analysis even reaching 100 percent. Internationally, these rates are extraordinary high, even in comparison with other European countries such as Italy (67 percent and, later, 78 percent) , Estonia (80 percent), England & Wales (85 percent) and France (80 percent)
https://journals.sagepub.com/doi/full/10.1177/14773708187648...