Why was Charles Sobhraj called the Bikini Killer? Updated: 3 Jan 2021, 16:47 CHARLES Sobhraj was a prolific serial killer who murdered young people during the 1970s throughout the Hippie Trail of Southeast Asia. His crimes led to him being dubbed the Bikini Killer. 3 What other nicknames did Charles Sobhraj have? He was called this because many of his victims were found dead in their bikinis. The attire of the murdered tourists led to the killings being sometimes referred to as the Bikini Murders. He was also branded The Serpent, a nickname used as the title for BBC One's new drama, due to his ability to 'slither' away from the police.