The prize is the top literary honor in the UK and comes with an award of $78,000.
Using the attempted assassination of Bob Marley in the 1970s as a springboard, it delves into Jamaican politics, gang wars and drug trafficking.
Judges called the novel the “most exciting book” on this year’s list.
“It’s a crime novel that moves beyond the world of crime and takes us deep into a recent history we know far too little about,” said Man Booker chair Michael Wood.
“It is not an easy read. It is a big book. There is some tough stuff and there is a lot of swearing—but it is not a difficult book to approach.”
Killings does include a gay character, the lethal criminal Weeper, and James says “it was very important to me that there were gay characters in the book—to reflect the gayness and hypocrisy in Jamaica.”
James, 35, said he had to leave his homeland just to be able to do simple things: “You might want to walk down the street and hold somebody’s hand one day. When you grow up in a homophobic country, you’re sitting on a time bomb.”
Before coming to the States and taking a job at Macalaster College in Minnesota in 2007, he recalls living in fear.
“I was so convinced that my voice outed me as a fag that I had stopped speaking to people I didn’t know,” he wrote in an essay in the New York Times. “The silence left a mark, threw my whole body into a slouch, with a concave chest, as if trying to absorb impact.”
“I bought myself protection by cursing, locking my lisp behind gritted teeth, folding away my limp wrist and drawing 36-double-D girls for art class. I took a copy of Penthouse to school to score cool points, but the other boys called me ‘batty boy’ anyway — every day, five days a week. To save my older, cooler brother, I pretended we weren’t related.”
In addition to Seven Killings, James is the author of John Crow’s Devil and The Book of Night Women,
He hopes the award will draw attention to the robust literary scene in his homeland.
“There’s this whole universe of really spunky creativity that’s happening,” he said. “I hope it brings more attention to what’s coming out of Jamaica and the Caribbean.”