What actually killed the crime wave in NY during the 70s was that wages got better
People were less poor and there were a lot more opportunities for societal advancement.
It’s easy to join a gang and be a menace to society when you have no avenues to improve yourself as a young person. Only option was the streets.
That might not have really answered your question but it’s a reoccurring theme throughout the years, the better it got for poor people the less overall crime and destitute the city got. Once that happened and crack decimated the black communities there was a slow but gradual process of gentrification.