A UK judge on Friday sentenced a man to life in prison without parole for the murders of four young gay men.

Serial killer Stephen Port met his victims online.

A jury on Wednesday convicted Port, 41, of using gay dating sites to lure the men to his apartment in east London, where he spiked their drinks with lethal doses of the date rape drug GHB. Once the men were unconscious, he raped them and dumped their bodies in and around a nearby graveyard. Two of the bodies were found by the same person, who alerted authorities.

Port was also found guilty of four rapes and four sex assaults against several other men.

Peter Tatchell, a prominent LGBT rights activist, accused the police of “sexuality bias” and questioned why they had not linked the deaths sooner.

“If four young well-off women had been murdered on Mayfair, I believe the police would have made a public appeal much sooner and mounted a far more comprehensive investigation,” Tatchell told reporters.

Police believe Port may have drugged and assaulted other men and have urged the victims to come forward.