[1] He has written articles for WWE magazine, Playboy, Men's Journal, HuffPost, Maxim and The Village Voice.
He previously was a producer Geraldo at Large, a prime-time television program on Fox News, America's Most Wanted and Forensic Files''.
In December 2010, St. Martin's Press released Love Hurts, the story of the Caffey family murder in rural Texas and Greenberg's second true-crime book for the publisher.
The True Crime Blotter of Rock 'n' Roll," published by Backbeat, profiles 21 deaths related to the music industry.
Greenberg traveled to Stockholm, Sweden to interview Anna Wohlin, the former model and girlfriend of Brian Jones, who was the last survivor who had been present at his estate when he died in 1969.
Sports Illustrated praised the book's "elegant prose, and Library Journal wrote, "Professional wrestling fans and historians will be gratified."
He also co-authored a number of biographies of professional wrestlers, including Freddie Blassie, Ric Flair,[5] and Superstar Billy Graham.