A Crime Prevention Research Center study found 57 percent of U.S. firearm murders occurred in 2 percent of counties, versus 53 percent of all murders in those counties. In 2025 the worst 1 percent of counties, with 20 percent of the population, accounted for 40 percent of murders, down from 41 percent in 2024, and the worst 2 percent, with 30 percent of the population, accounted for 53 percent. John Lott wrote that 1,981 counties holding 17 percent of the population had no firearm murders and 453 more holding 8.92 percent had one, so 78 percent of counties had zero or one firearm murder and 4.9 percent of firearm murders occurred where 25.97 percent of people live. Biden carried all but one of the highest-firearm-murder counties in 2020; Harris carried 25 of 31 in 2024. Where city and county borders differ, an average of 74 percent of murders in the worst 1 percent of counties occurred in the major city, which voted more Democratic than the county as a whole.