The 24-year-old model died after a night out partying in the city with friend Hilda Marcela Cabrales-Arzola, who remains in critical condition in hospital.
Around 12 hours after the women were last seen, Giles’ lifeless body was left on the sidewalk outside Southern California Hospital in Culver City, where she was pronounced dead.
Her mother, Dusty Giles, has said she believes her daughter was drugged and attacked before being left at the hospital by a group of men who disguised their identity.
“Maybe they gave her something that incapacitated her and then you know, who knows what happened at that point,” Mr Cilliers told The Independent.
“That is my worst fear but also my working theory. We will just have to wait and see wait and see what the medical examiner comes back with, supposedly that should be any day now.”
Mr Cilliers said police have identified the men and questioned them about what happened.
“The bandanna guys, the police have already spoken to them, they know they were partying with the girls, and that they dropped off the girls as soon as they overdosed,” he said.
“Does that mean Christy overdosed at 5pm then they took her to the ER, then the other girl stayed back at the apartment and did drugs and overdosed later? That doesn’t make any sense.”
Mr Cilliers, who was visiting San Francisco last weekend, said that his wife had only been at the apartment in West LA in the early hours to protect her friend.
“Christy was trying to leave there at 5.30am, she was worried for her safety and for her friend’s safety.
“The only reason she was still there in the first place was that she did not want to leave her friend alone
“She would never leave a girlfriend behind, you know, the worst thing she would want ... was for something like this to happen to her girlfriend, and unfortunately it happened to both of them.
“They ordered an Uber at 5.30am. They were never heard from again until they were dropped off with no signs of any vitals and their bodies were already cold at 5pm for Christy, and 7pm for Marcela – it is all very suspicious.”
Mr Cilliers has said that heroin was found in Ms Cabrales-Arzola’s system, and that neither woman would take the drug voluntarily.
Mr Cilliers says he and his wife went on their first date on Valentine’s Day 2019 after meeting at a London art gallery and married just months later.
“This is all heartbreaking. Our relationship was the most fairytale relationship you could possibly imagine. She was an incredible woman,” he said.