Laughable. Make the claim and don't support it.
Without banning guns or more gun control.
https://www.theatlantic.com/politics/archive/2016/04/what-caused-the-crime-decline/477408/
What Caused the Great Crime Decline in the U.S.?
After decades of soaring levels of homicides and drug violence, the country’s crime rate plunged dramatically over the last 25 years. What happened?
...
By decade’s end, the homicide rate plunged 42 percent nationwide. Violent crime decreased by one-third. What turned into a precipitous decline started later in some areas and took longer in others. But it happened everywhere: in each region of the country, in cities large and small, in rural and urban areas alike. In the Northeast, which reaped the largest benefits, the homicide rate was halved. Murders plummeted by 75 percent in New York City alone as the city entered the new millennium.
The trend kept ticking downward from there, more slowly and with some fluctuations, to the present day. By virtually any metric, Americans now live in one of the least violent times in the nation’s history.
But the forces that drove the Great American Crime Decline remain a mystery. Theories abound among sociologists, economists, and political scientists about the causes, with some hypotheses stronger than others. But there’s no real consensus among scholars about what caused one of the largest social shifts in modern American history.