One more item to this. This is rate per population. In terms of overall hard numbers:
https://ucr.fbi.gov/crime-in-the-u.s...tables/table-1
So yes while murders rate per 100,000 inhabitants has dropped over the course of that time frame by 30-40% the overall reduction in murders was 1,000 instances. Looking at the FBI data the core areas of decreases classified as a violent crime were robbery and assault which fell by hundreds of thousands of instances. To me that is a more scary statistic, we've decided to stop assaulting and robbing others, but decided to keep it rolling on the whole murder thing.
Not even going to get in to the whole conflict of "all this immigration has made us more susceptible to crime" argument during the same period while touting "crime is down overall" since I'm sure the counter argument is the immigrants took it upon themselves to commit the remaining murders, taking the place of hard working american murderers just like they took all the jobs...