murder clearance rates
The Marshall Project has an intriguing article on how often homicides are “cleared” – meaning that the police have closed the case by identifying a likely killer. The big fact is that American murder clearance rates have gone down. As the chart above shows, homicide clearance has dropped by about a third.
Why? The authors offer a few reasons. For example, gaps in clearance rates for Whites and Blacks have grown a little, explaining some of the decrease over time. Another reason is that police departments now often use DNA evidence and other tools that require testing, which leads to delays and dropped cases. There has also been a massive shift in resources from homicide investigation to drug enforcement.
Here’s my guess: Before, there was a remarkably low barrier for getting a murder conviction. One reads cases of juries convicting people based on a single witness. In modern times, we simply have higher standards, which means that fewer cases will be cleared.