A Chinese man has admitted to drugging and sexually assaulting three women while he was a Ph.D. student at the University of Southern California. Sizhe Weng, 30, has been charged with multiple felonies and is being held without bail.

A prosecutor’s motion stated that Weng, who also goes by Steven, drugged the women through both a powder in their food and drinks, as well as through syringes and tubing in their anuses, before sexually assaulting them and taking photos of them, per the Los Angeles Times. Prosecutors said that Weng tied two of the women up with straps and had manipulated their bodies into sexually suggestive poses.

The September 2 motion from LA County Deputy Dist. Atty. Catherine Mariano stated that Weng described the assaults “at length and in detail” to LA Police Department detectives.

In the motion, Mariano argued that Weng should be held without bail. Investigators reportedly overheard him saying in his jail cell that if he was let out on bail, he would return to China, which has a no-extradition treaty with the US. Weng’s jail cell had recording equipment placed in it.

Investigators reportedly found sexually explicit Polaroid photos at Weng’s residence depicting the three victims, as well as a medicine bottle containing a liquid that tested positive for midazolam, which is used for sedation during minor medical procedures. Weng allegedly injected the drug into the victims’ anuses. Prosecutors said that Weng had acquired the drugs from a supplier in Germany.

Investigators also found several snake and pinhole cameras, leather straps, syringes, red tubing, and dental mouth devices, as well as electronic devices and flash cards “believed to contain additional images and/or videos of defendant drugging and sexually assaulting women.”

The assaults occurred on December 10, 2021, August 1, 2022, and between 2023 and 2024, prosecutors said, but Weng wasn’t alerted to the authorities until German officials reached out regarding his involvement in a sex crimes and drugs investigation in the country.

LAPD Deputy Chief Alan Hamilton said, “As soon as we became aware of actionable information, we opened an investigation. It took us a while to catch up to all the activities this individual has been involved in, in LA.”

The motion stated that Weng’s first victim was a childhood friend, Jane Doe 1, who traveled with him in December 2021 to San Diego. On that trip, Weng brought the drugs as well as leather straps and dental devices. He reportedly placed crushed benzodiazepine pills in small glass vials with water and put the mixture in her drink when she wasn’t looking.

Upon returning to their hotel room, Weng reportedly injected her with Midazolam using the tubing and a syringe. Prosecutors said he also soaked a towel with sevoflurane, an anesthetic, and covered her nose and mouth with a mask.

Upon losing consciousness, the woman was tied up with leather straps and raped vaginally, before she was raped anally after she resisted the attack by kicking. The motion stated that Weng “filmed and photographed Jane Doe 1’s body in sexually compromising positions.” In one image, she “appeared unconscious with a plastic dental device in her mouth exposing her gums and teeth,” while other images showed her “placed in different positions highlighting her vaginal and anal areas while her legs remained bound with leather straps.”

Jane Doe 2, the next victim, was a friend who had come from China to study in the US. She was picked up at the airport by Weng, who reportedly spiked a drink she bought with crushed benzodiazepines. She blamed her tiredness on jet lag and went to bed at her Airbnb, prosecutors said.

Similar to the first victim, Weng was said to have administered midazolam anally and covered the victim’s mouth with the sevoflurane-soaked cloth. He “hog tied her wrists and ankles with straps and proceeded to penetrate her vagina and her anus with his penis.” She was photographed while unconscious and “bound in different positions.”

In 2023 and 2024, a classmate in Weng’s doctoral program, who he considered to be a close friend, Jane Doe 3, was drugged at her home by Weng multiple times. The motion stated that the first time, her poke bowl was spiked with crushed benzodiazepine pills and Weng groped her after she fell asleep, while the other two times saw Weng use the crushed pills in her food or drink, anally inject her with midazolam, and then put his fingers in her anus and touch her body. She was also photographed while unconscious and nude.

Weng has been charged with one felony count of forcible rape; two felony counts of sodomy by controlled substance or anesthesia; one felony count of rape by controlled substance; and four felony counts of sexual penetration by controlled substance or anesthesia, per the LA County District Attorney’s Office.

Weng entered a master’s program at USC in 2018 and completed his doctorate in May. He graduated from China’s Lanzhou university with a bachelor’s degree in theoretical physics and has coauthored more than two dozen academic papers.

Los Angeles County District Attorney Nathan J. Hochman said in a statement, “No one should ever have to endure the trauma of being drugged, sexually assaulted and stripped of their ability to consent. Prosecutors in my office’s Sex Crimes Division and our law enforcement partners will not rest until the defendant is held accountable for these horrific acts. We want every victim to know that their voices matter and we will fight to ensure you are heard. We urge additional victims, whether you live locally or abroad, to contact the LAPD’s Robbery-Homicide Division to report any suspected crimes.”

USC said in a statement, “Although we cannot discuss individual cases due to student privacy laws, we can confirm that the university had already taken appropriate steps to bar the individual in question from campus pending resolution of the criminal proceedings. USC has not received any reports from individuals potentially impacted.”