One simple trick works to help reduce violence in high-crime areas, studies show. So Dallas is trying it.

Dallas is deploying a crime-fighting solution that, simple as it may sound, has quickly yielded results: lights.

The city is converting 1,000 public streetlights to brighter LED bulbs and adding 200 lights to dimly lit areas where crime is most prevalent, in an effort primarily focused on reducing violence. Most upgrades are in southern Dallas but a few are in the northern part of the city.

The idea is that lights reduce opportunities for crime. The mayor’s Task Force for Safe Communities recommended in its January 2020 report putting outdoor lights in crime hot spots.

In December and January, Dallas installed 76 new streetlights to a corridor of South Malcolm X Boulevard near the Marburg Street intersection.

As of late March, violent crime in the first three months of the year was down near that intersection about 16% over the same time last year, and 911 calls also went down about 44%, according to the mayor’s office.

“It’s still early in the year, but this is an extraordinarily promising start,” Mayor Eric Johnson said. “It’s something we can build on.”

Adding lights to dark city streets is a proven strategy to curb crime.

New York City experimented with adding lights to public housing developments and studied its effect on crime. A 2019 report on the experiment showed at least a 36% reduction in serious crimes committed at night over a six-month period.

“By enhancing visibility, lighting has the potential to change crime through many channels, including by empowering potential victims to better protect themselves and by making potential offenders more aware that a public space has witnesses or that police are present,” authors wrote in the study, Reducing Crime Through Environmental Design: Evidence from a Randomized Experiment of Street Lighting in New York City.

For the study, temporary streetlights were randomly placed in public housing developments between March and August 2016. A review of crime reports in those communities that got more lighting showed sizable reductions in crime, the study found.

If crime continued decreasing at the same pace, the researchers estimated, the social costs of crime saved would outweigh expenses of installing the lights.

Shooting homicides cost the U.S. more than $229 billion annually — about $400,000 per victim — in direct expenses such as emergency services, police investigations, prison costs and indirect costs, including loss of a person’s wages and quality of life, according to a 2015 analysis by Ted Miller of the nonprofit Pacific Institute for Research and Evaluation.

Researchers in the New York experiment predicted lighting upgrades would save communities about $770,000 each year using estimated social costs of crime.

Dallas city officials said they’re spending $500,000 on upgrading and implementing lights.

Michael Rogers, director of Dallas’ transportation department, said the department’s biggest line item is the energy cost of the current lights: $17 million, which includes Oncor’s and TXU Energy’s fees.