Eric Rauchway posts a chart illustrating Douglas Eckberg’s reconstruction of the correct homicide rate in the early 20th century United States, which was underestimated by the census bureau at the time:
I think this illustrates some of the dynamics of crime control. When there’s relatively little murdering happening, it’s easier for the crime control apparatus, from the police to the prisons and all the rest, to be pretty effective at keeping murder in check. Consequently, the murder rate stays low. But when it’s high, the system gets taxed and the tendency is for there to continue to be a lot of crime. If we were able to get ourselves back down to the murder rate that prevailed from the mid-thirties to the mid-sixties the benefits would be enormous, and it probably wouldn’t be that hard to sustain ourselves at the lower level.
Meanwhile, the United States is strikingly more murderous than other rich democracies and has been for a long time.