I think there's a much simpler and more historically universal reason: murders go up in bad economic times. Inflation is high, inequality is increasing, people are losing or have lost their jobs, and who has suffered this seems pretty random, particularly since other groups (like software engineers in 2020/2021, solar installers in 2022, tradespeople in 2023) are doing just great. All this makes people on the losing side very angry. Some angry people kill people.

There was a similar spike in murders during the 1970s and early 80s, and during the 1920s and Great Depression.