Sam Quinones has written a fascinating article at Pacific Standard about the decline of gang violence in Los Angeles.
The story is complex, but Quinones credits the decline in part to the following factors: (1) an increase in the number of officers in the field; (2) the use of CompStat to measure the effectiveness of police interventions, to guide subsequent interventions, and as criteria for the retention and promotion of police commanders; (3) the use of RICO (federal anti-racketeering laws) to prosecute and incarcerate large numbers of street gang foot soldiers; (4) changes in gangs' culture and politics (for example, the fact that the Mexican Mafia has alienated many gang members because of its widespread use of "greenlights" or death warrants against its enemies); and (5) the increase of real estate prices and gentrification in neighborhoods formerly dominated by gangs.
Among the other revelations, the article has this to say about a spate of race-related killings in the bad old days of gang violence, and the change since then:
In many of these neighborhoods, Latino gangs had taken to attacking and killing random black civilians, turning themselves into the leading regional perpetrators of race-hate crime. . . . The last three times I’ve been to Hawaiian Gardens, I’ve seen nothing on the walls, and young black men freely visit taco restaurants on the main drag, something that would have been inconceivable a few years ago.Now, street gangs continue to exist, and they continue to wield a great deal of wealth and power. But a lot of their drug dealing and other criminal enterprises no longer happen on street corners, and in relative terms there is less violence than their used to be. That is great and surprising news. Hopefully the trend continues.