Brazil decreased its homicide rate by 13% in 2018, the lowest since 2011.

Security experts warn that Brazil's newly elected president, Jair Bolsonaro, could jeopardize this achievement.

He is advocating for looser gun laws, and more latitude for police to use deadly force.

Brazil reduced its homicide rate by 13% last year, ending a years-long streak of record violence, according to a new report released Wednesday.

The annual Monitor of Violence report recorded a rate of 24.7 homicides per 100,000 in 2018, the lowest since its records began in 2011. The overall number of homicides was 51,000, a seven-year low.

The report is produced every year by a group of academics, policy experts, and journalists, and plays a large part in Brazil's public discourse on its levels of violence, which remain among the worst in the world.

Public security experts welcomed the results, but warn that far-right president Jair Bolsonaro, who was inaugurated last month, could undo the changes by implementing campaign pledges on policing and gun ownership.

Renato Sergio de Lima and Samira Bueno, experts with the Brazilian Forum of Public Security, wrote on the G1 news portal: "Any increase in homicides in 2019 will be directly related to the president's irresponsible attitude determined exclusively by his populist ideology."

In a country that is plagued by shootings, muggings and gang wars, violence was a hot topic during the elections in October.

Bolsonaro's winning campaign included a pledge to give police a "carte blanche" to kill.

"A good criminal is a dead criminal," was one of his slogans on the campaign trail.

Bolsonaro, a former military officer, is also a gun enthusiast, and often poses with his hands in the shape of a pistol — as depicted here on a recent cover of VEJA magazine.

Last month, he signed a temporary decree that made it easier for civilians to own firearms, so "that good citizens can have peace inside their own homes."

De Lima and Bueno believe this decree could send the homicide rate up again.

"We have to combat the populist discourse that defends the strategies that didn't work in the past 75 years," they wrote.

The security experts attribute last year's success to improved cooperation between institutions like the police and prosecutors.

Brazil's 26 states have also focused on financing and strengthening anti-violence initiatives - for example, the southern state of Santa Catarina invested in body cams and other technologies for police officers.

The researchers believe these trends are necessary to prevent the homicide rate from rising again.

"We can't become hostages to well-intentioned prophets or saviors of the nation," they wrote.