Brazilian police killed more than 11,000 people between 2009 and 2013, with an average of six killings a day, a public safety NGO announced on Tuesday.
The study by the Sao Paulo-based Brazilian Forum on Public Safety said police had killed 11,197 people nationwide over the past five years, while law enforcement agents in the United States had killed 11,090 people over the past 30 years.
"The empirical evidence shows that Brazilian police make abusive use of lethal force to respond to crime and violence," the report said.
There were 416 people killed last year in Rio de Janeiro state, giving it the highest per-capita rate for 2013.
The study also said 50,806 people were killed in all homicides last year, about one person every 10 minutes.
Nearly 70 percent of the homicide victims were black and more than half were ages 15 to 29, it said.
In addition to using excessive force, Brazilian police frequently execute suspects, said Bruno Paes Manso of the University of Sao Paulo's Center for the Study on Violence. He called it "a practice rarely investigated."