INDIANAPOLIS, Ind. (WOWO): Someone is killed with a gun in Indiana every 12 hours, according to a new report, earning the state the ranking of 20th in the nation for gun violence.

Researchers with the Center for American Progress looked at ten types of gun violence – including suicides, homicides and mass shootings – that occurred over the 10 year period from 2005 to 2014. Report co-author Chelsea Parsons, vice president of guns and crime policy at the Center for American Progress, said the states with the strictest gun laws had the lowest levels of violence.

“What we found is that the ten states that have the weakest gun laws collectively have rates of gun violence that are more than three times higher than the ten states with the strongest gun laws,” Parsons said.

The report gave Massachusetts the top score for laws that are effective at preventing gun violence. Louisiana was at the bottom.

Researchers found that laws requiring background checks, trigger-lock rules and training requirements coincided with lower rates of gun violence, particularly in cases of domestic violence.

“Making sure that all gun sales in the state are required to undergo a background check will help keep guns out of the hands of domestic abusers, who are not supposed to be able to buy them,” Parsons said.

According to the Centers for Disease Control and Prevention, from 2005 to 2014, 167 people in Indiana died in gun-related accidents. Nearly three in 10 were under age 21. And while African-Americans make up close to 10 percent of Indiana’s population, they account for 62 percent of the state’s gun-related homicide victims.