Crime in New York City was so bad in the 1970s and ‘80s that even cops could only imagine an apocalyptic solution: blow it up and start from scratch.

“A torpedo might help,” said New York Police Department officer Robert Friedman in a 1982 interview with the New York Times. “If you were looking for a block that ought to be destroyed, and you could run a torpedo down it, 100th Street would be your best bet.”

East Harlem was a rough spot back then. Drug deals were made in broad daylight and murder-related headlines splashed across newspapers. But now, East Harlem (much like the rest of Harlem) is becoming gentrified, attracting contractors and injecting a host of new people into the neighborhood. A few years ago, the Timescalled it New York’s next hot neighborhood.

It points to a larger trend: Over the last 30 years, New York, overall, has gotten safer. In 1990, about 2,240 people were murdered. According to AmericanViolence.org 312 people were murdered in 2017.

And New York is a microcosm for the rest of the country. NYU sociology professor Patrick Sharkey says American violent crime has plummeted since the early 1990s.

“D.C. used to have the highest murder rate in the country and it has fallen by 75 percent or more since the early 1990s,” said Sharkey, who’s the author of the new book, "Uneasy Peace: The Great Crime Decline, the Renewal of City Life, and the Next War on Violence."

“The most visible changes that have taken place are in places like L.A., D.C. and New York, but there are a whole bunch of cities around the country where violence has fallen by more than half and where the cities have really started to transform,” he said.

Despite the progress, many Americans don’t believe the numbers. Sharkey says the rhetoric from President Trump is partly responsible, but other players are culpable, too. Local media often uses inflammatory crime reporting to drive up ratings, advocates play up the news of violence so supporters don’t get complacent, and some people simply don’t trust government data.

But American cities, on the whole, are getting safer. And there are many factors that are responsible for that.

“[In the early 1990s] a whole bunch of changes happened,” Sharkey says. “We expanded police forces, which came about because of President Clinton's crime bill. Mass incarceration continued to rise and private security guards proliferated.”

But one factor, in particular, is often overlooked in this analysis: community groups. Sharkey says that investment into places like the Boys & Girls Club of America and substance abuse organizations started getting more funding and began drastically mobilizing in ways they hadn’t before. And the work they did helped reform often-overlooked areas of cities.

“They stabilize a community,” Sharkey says. “They ensure that a neighborhood is not going to go downhill even when it goes through a bout of joblessness or concentrated poverty. These are the types of organizations that are crucial to making sure that violence doesn't emerge. We've just never provided the investment to make sure that these types of institutions and organizations are sustained over time.”

But community groups can only do so much, Sharkey says. The tactics that got us to a less violent America — policing, private security, mass incarceration — should be reexamined. He says the methods are outdated, and were meant for a different era of the American city.

“For the past 50 years the default model has been to focus on punishment as a solution to violence,” Sharkey says. “I think we now have sufficient evidence to propose a new approach. An approach that focuses on investment. I don't just mean investment in community residents and organizations. I'm also talking about investment in police departments, so that there is actually a pathway forward for changing the way that law enforcement interacts with residents.”