Dennis Lehane was in Boston, Massachusetts. He grew up in the suburb of Dorchester, where many of his novels are set. His father, an immigrant from Ireland, was a foreman for Sears & Roebuck, while his mother, also from Ireland, worked for a public school. Lehane attended Eckerd College, where he began to write. In 1994, he published his first novel, A Drink Before the War, which introduced Patrick Kenzie and Angela Gennaro, private investigators in a relationship who recur in Lehane's novels.
Over the next years, Lehane followed that novel with several more following the characters, including Darkness, Take My Hand, Gone, Baby, Gone, and Praying for Rain, in the late nineties. During that time, he also wrote Mystic River, which brought him to a large national audience because of the 2003 film adaptation by Clint Eastwood, starring Sean Penn and Kevin Bacon. Gone, Baby, Gone was filmed in 2007, and resulted in an Oscar nomination for Casey Affleck, who played Patrick Mackenzie. Shutter Island, which was written in 2003, was turned into a film by Martin Scorsese in 2010, starring Leonardo DiCaprio and Mark Ruffalo. The three films cemented Lehane's reputation as one of the best nationally known crime writers. He has also written for The Wire, together with Richard Price and George Pelaconos, crime writers of equal stature.