Police officers patrolling in the Nordeste de Amaralina slum complex in Salvador,
Bahia State, in 2013.
Of the 50 cities on the list, 41 are in Latin America, including 21 in Brazil.
"Narcotics are the biggest black market earner of all. Estimated to be worth more than three hundred billion dollars a year, the global industry has pumped huge resources into criminal empires decade after decade," wrote Ioan Grillo the author of "Gangster Warlords: Drug Dollars, Killing Fields, and the New Politics of Latin America."
"So that amount of money, $100 billion a year, 10 years, a trillion dollars, 30 years, $3 trillion. That amount of money pumps in these organizations ... buying more guns, paying more assassins, bribing more police, bribing more politicians ... and that is why the region right now, Latin American and the Caribbean, are at a boiling point," Grillo told Business Insider.
The council's ranking contains cities with populations of more than 300,000 and does not count deaths in combat zones or cities with unavailable data, so some dangerous cities may not be represented on the list.
50. Obregón, Mexico, had 28.29 homicides per 100,000 residents.
Patrons eat at a taco stand, as the body of a man lies on the pavement, in Ciudad Obregon August 10, 2010. According to local media, the man died after suffering a fatal heart attack.
49. Maracaibo, Venezuela, had 28.85 homicides per 100,000 residents.
People blocking a road in protest after a large blackout affected five states in Venezuela, in the western city of Maracaibo, in 2011.
48. Macapá, Brazil, had 30.25 homicides per 100,000 residents.
47. Johannesburg, South Africa, had 30.31 homicides per 100,000 residents.
A soldier standing guard as the police raided a hostel in Johannesburg's Alexandra township on April 23.
46. Victoria, Mexico, had 30.50 homicides per 100,000 residents.
A soldier standing guard at the site of a car-bomb attack outside the broadcaster Televisa in Ciudad Victoria in Mexico.
45. Pereira, Colombia, had 32.58 homicides per 100,000 residents.
Troops unloading the body of a FARC rebel from a helicopter in Pereira, Colombia, in 2006.
44. Curitiba, Brazil, had 34.71 homicides per 100,000 residents.
Police officers clashing with teachers during a protest in Curitiba in Parana state on April 29.
43. Porto Alegre, Brazil, had 34.73 homicides per 100,000 residents.
Riot police officers detaining two men during a protest against the 2014 World Cup in Porto Alegre in 2014.
42. Nelson Mandela Bay, South Africa, had 35.85 homicides per 100,000 residents.
South African soldiers seen before welcoming the funeral cortege carrying the coffin of former South African President Nelson Mandela to the Union Buildings in the capital Pretoria on December 12, 2013.
41. Durban, South Africa, had 35.93 homicides per 100,000 residents.
Striking workers of the South African Municipal Workers Union marched through Durban in 2011.
