[video=youtube;pB73OPtowN8]http://www.youtube.com/watch?v=pB73OPtowN8[/video] [video]http://on.rt.com/alluai[/video] video of Rio de Janeiro police in a helicopter firing on a moving car in a populous slum has sparked a probe. Footage emerged of the high-octane chase a year after it happened, raising concerns over the excessive use of police force. The video that brought the incident to Rio authorities’ attention was released on Sunday by Brazilian media outlet Globo Noticias. The footage from the helicopter’s camera shows how officers tracked Marcio Jose Sabino Pereira – known as ‘The mathematician’ –through the Coreia slum in western Rio. The suspect got into a car and drove off, and during the pursuit police opened fire on the moving vehicle with an automatic weapon. The crossfire from the shootout struck the road around the car and the surrounding buildings. Perreira was found dead in the vehicle the next day on May 12. Rio police chief Martha Rocha described the use of force by police as “disproportional,” and said that a probe had been opened into the incident on April 30. Secretary of Public Security Jose Mariano Beltrame told Globo TV that police sometimes make mistakes. “We have police who make mistakes, we have police that do it right and our policy is always to look for the best for the people,” he told Globo, adding that the incident was highly out-of-the-ordinary for the police force. The officer who piloted the helicopter and was in command of the operation, Adonis Lopes de Oliveira, will be questioned on Wednesday by magistrates in connection with the shooting of Perreira. Marcio ‘The Mathematician’ Perreira was one of Rio’s most prolific drug dealers, wanted on 26 charges of drug trafficking, conspiracy to traffic and homicide. Rio de Janeiro’s favelas are a hotbed for violence and crime, with regular police incursions to wheedle out drug traffickers. Since 2003, Rio police have killed more than 11,000 people in connection with the drug trade. Concerns have been raised over security in Rio for the 2016 Summer Olympics, and huge investments have been made by the city’s government to cut down on delinquency in the city’s infamous favelas. There have been accusations that police are forcefully repressing residents in the city’s poorer areas in preparation for the Games.