Interesting that the Northeast, where no state has the death penalty, saw a 5.6% decrease in murders while the South, where virtually every state has the death penalty, saw a 3.6% increase. https://ucr.fbi.gov/crime-in-the-u.s/2017/preliminary-report/tables/table-2

In fact virtually all the crime increase was in the more conservative midwest and south. Crime decreased in all categories in the Northeast and most categories in the West.

I have never found the regional numbers in the semiannual report meaningful. They are too coarse-grained to be of any real use.

Regional statistics overgeneralize. For these preliminary reports, large cities provide more useful information. For example, in Miami violent crime and property crime were down across the board, while Chicago and Baltimore both saw significant increases. What role the death penalty plays in this is hard to know, but differences in policing appear to matter. On the west coast, four large cities with state or local policies that discourage pro-active policing and have reduced consequences for crimes; Los Angeles, San Francisco, Portland and Seattle have all seen increases in violent crime. California is particularly interesting because of its ultra progressive policies on illegals, drugs and habitual criminals. Of the state's 73 large cities, 41 had increases in violent crime, 25 had increased homicides, 39 had increased rapes, 43 had more robberies and property crime was up in 32. The state's large cities saw similar increases last year.