Does your state have strict gun laws? Chances are it saw a drop in gun homicides.

The states with the strongest gun restrictions saw a much greater drop in shooting homicides last year than those with less stringent gun laws, according to a study released Wednesday.

That held true for large cities in those states as well. Detroit, Los Angeles, Portland, Oregon, and San Jose, California, for example, saw a greater decline than big cities in states considered to have weaker gun laws.

Overall, 36 states saw gun homicide rates drop last year compared to 2022, according to the left-leaning Center for American Progress. While homicides have not yet returned to pre-pandemic levels, they have started to decline from the high they reached during the global health crisis. The number of homicides nationally last year dropped by about 12%.

“We're talking about a historic decline right after a historic surge,” said Chandler Hall, senior policy analyst for gun violence prevention at the center and the study’s author.

Hall discovered the link between the decline in gun homicides and a state’s gun laws when he compared crime data against a state’s gun grade. States that got an “A” from the gun control advocacy group Giffords saw on average a 13.7% drop in gun homicides, according to the study. States that received an “F” also saw a decrease, but by a much smaller amount—5.1% on average.

California, which received an A, saw gun-related homicides drop by 15.9%. New York, which got an A-minus, saw a 20.8% decline.

Only 14 states saw gun homicides increase. Of those, six—Alabama, Alaska, Idaho, Mississippi, Tennessee and Utah—received an F. Maine, where the number more than doubled, got a D.

“Weak state gun laws likely contributed to the lack of progress in those places,” Hall wrote in the analysis.

In an interview, however, Hall said that he is concerned states’ progress in reducing gun homicides could be undermined by several U.S. Supreme Court rulings, including the 2022 decision in New York State Rifle & Pistol Asso­ci­ation v. Bruen and possibly by an upcoming decision over whether states can prohibit people with restraining orders for domestic violence from having guns.

Whether a change in the legal landscape will impact the grades given by Giffords remains to be seen. The group considers a number of factors when assigning them, said Lindsay Nichols, policy director for the Giffords Law Center, which is part of the advocacy organization founded by former Congresswoman Gabrielle Giffords after she was shot in the head during a 2011 public appearance outside an Arizona Safeway.

Among the factors, Nichols said, is whether states require background checks for all gun sales, have a waiting period for purchasing weapons and whether the state funds community violence intervention programs. The group also considers whether survivors of gun violence can file lawsuits against the gun industry, whether they have laws that prevent gun trafficking, require the safe storage of weapons, and have restrictions on assault weapons, bump stocks, and unserialized and untraceable “ghost guns” that can be bought online and assembled at home. 

The center’s conclusion is likely to be challenged by gun rights advocates, who cite a number of other factors for the reduction in homicides, including the end of the pandemic. And Hall acknowledges there are some “outliers” in which the change in the number of homicides doesn’t appear to follow the strength of the states’ gun laws. 

Georgia, for instance, received an F from Giffords, but still saw an 11% decline in gun homicides. Hawaii, which got an A-minus, saw the number of gun homicides rise by 35%. Delaware and Rhode Island, which both received B-plus, saw their number of gun homicides rise by 18.4% and 60% respectively.

Still, Hall said the overall numbers support his assertion that “stronger gun laws save lives and prevent needless deaths.” The “stark contrast” in numbers between states with strict laws and those without “should alarm state leaders who are denying the passage of common sense gun laws that are keeping residents in other states safer,” he wrote in the analysis. ”Until lawmakers everywhere get serious about protecting people over guns, there will be two Americas when it comes to public safety.”

The analysis further found that cities in states that received an A or A-minus saw gun homicides drop on average by 19.4%. Meanwhile, the gun deaths in cities in states that received an F dropped on average by only 5%.

Detroit, which saw the greatest decrease, of 37.4%, is in Michigan, which received a B-minus. Of the 10 cities that saw the greatest decline, seven are in states with an A-minus grade. Among them: San Jose saw a 33.3% drop in shooting homicides. The number of gun deaths dropped by 31.6% in Portland, Oregon; 28.7% in Baltimore; 26.4% in Los Angeles; and 26.3% in San Diego.

One exception is Houston, which saw a 21.2% decrease—the seventh highest in the nation—despite Texas’ F grade.

Two cities contacted by Route Fifty said their state’s gun laws helped reduce gun homicides, but also said that actions they have taken have helped.

John Roble, a spokesperson for Portland Mayor Ted Wheeler, said he “appreciates and supports state-level efforts to strengthen gun laws,” adding that the city’s own “diverse approach to engage with people at the highest risk of gun violence” contributed to the drop as well.

The city, for example, hired street outreach workers called violence interrupters to engage with those at risk of becoming a victim or perpetrator of violence. The city has spent and will spend another $14 million over the next two years on violence prevention programs, including working with middle school students and giving 18 months of intensive case management for those considered to be most at risk of committing violence.

A spokesperson for San Jose’s police department, meanwhile, said it has worked to increase the number of gun seizures from 836 in 2020 to 969 in 2021 and 1,231 in 2022. The department also has a “close and trusted collaboration with our community, which has proven to be essential in addressing criminal activity in the city.”