Stephen Port, 41, from London, was convicted of killing Anthony Walgate, 23, Gabriel Kovari, Daniel Whitworth, 21, and Jack Taylor, 25, over a 15-month period between June 2014 and September 2015.
He was also found guilty of drugging or sexually assaulting seven other victims, who survived.
UK police are reviewing the chemsex-related deaths of 58 other men, previously dismissed as drug overdoses, amid fears some may be linked to Port.
