It took eight days for police to locate Andrew Cunanan, who had murdered at least four other people in the three months leading up to Versace's death.
Cunanan, who was also gay, killed himself as police closed in on him. A motive for the killing was never established.
D'Amico has had a tense relationship with Versace's family, including sister Donatella, who cut off contact with D'Amico after her brother's death.
Gianni Versace. Photo / AP
"My relationship with Antonio is exactly as it was when Gianni was alive. I respected him as the boyfriend of my brother, but I never liked him as a person. So the relationship stayed the same," Donatella Versace said in 1999.
Ryan Murphy is currently working on a new series called Versace: American Crime Story. Ricky Martin will play D'Amico, Zero Dark Thirty star Edgar Ramirez has been cast as Gianni Versace, while Penélope Cruz will play the designer's sister, Donatella.