Her decision to switch careers was influenced by the death of her mother who was murdered in New York in 1983 in a random hotel break in.
She is married to Bill Keller, former executive editor of The New York Times, then of The Marshall Project, and has two daughters, Molly and Alice.
Gilbey Keller's first job in journalism was at Roll Call newspaper on Capitol Hill in Washington D.C. and from there she went to work in the investigative unit of ABC News.
Following its publication Gilbey Keller became a feature writer for the London Sunday Times, specializing in English and American trials and headline crimes.
Over the years, she has written for The Spectator, The Literary Review, Vanity Fair, The New Yorker, Slate and The New York Times.