Details of Disappearance
Zhang was last seen in Urbana, Illinois on June 9, 2017. In April, she had moved from her native China to attend the University of Illinois (UI) as a visiting scholar. She had gotten her master's degree in environmental engineering at Peking University and was researching photosynthesis and crop productivity in soybeans and corn at UI.
On the day of her disappearance, she was running late to a meeting to sign a lease with a landlord. She was sighted on surveillance footage near the B-4 parking garage on north Goodwin Avenue at 2:00 p.m. Zhang had just gotten off a bus when a black four-door Saturn Astra hatchback pulled up beside her. She had a brief conversation with the driver, then got into the vehicle. She has never been heard from again.
According to her fiance, a classmate from Peking University whom she planned to marry in October 2017, studying in the United States had been Zhang's longtime dream and she was enjoying herself there. She planned to complete her doctorate at UI, return to China and take a position as a university professor.
She was devoted to her family in China, and called her parents every Saturday. She had been accepted at several universities, but chose UI in part because their financial aid would mean she wouldn't be a burden on her working-class parents. In her spare time she enjoyed playing guitar and singing.
The driver of the car Zhang got into turned out to be Brendt Christensen, who had earned his master's degree in physics from UI in May of that year. Christensen claimed he let Zhang out of the car a few blocks away. His Saturn Astra was located on June 28, and on June 30, Christensen was charged in federal court with Zhang's kidnapping. A photo of him is posted with this case summary.
Authorities learned that on the day of Zhang's disappearance, someone matching Christensen's description had been driving around in a black Saturn Astra posing as a police officer, and this person attempted to lure at least one other woman into his car. The woman was suspicious and refused to get inside the vehicle.
A forensic examination of Christensen's phone revealed he had visited an online fetish forum called "Abduction 101" and subforums called "Perfect Abduction Fantasy" and "Planning a Kidnapping". Police also noticed he had cleaned his car's front passenger door more thoroughly than the other doors and thought he was trying to destroy evidence.
In October, Christensen was additionally charged with kidnapping resulting in death. The indictment said he acted "in an especially heinous, cruel or depraved manner, in that it involved torture or serious physical abuse to the victim." The prosecution is seeking the death penalty against him.
Christensen attended a vigil for Zhang at the UI campus on June 29, and so did his girlfriend, whom the police had convinced to start recording his conversations. She secretly recorded hours of his conversations and later turned them over to the FBI, who was by then investigating Zhang's disappearance.
At the vigil, Christensen talked about the sort of person that makes an "ideal victim." In another recording, he said he kidnapped Zhang and took her to his apartment, and that she "fought and resisted" him. He talked about how he had raped her, hit her in the head with a baseball bat, stabbed her in the neck and cut her head off. He also claimed he was a serial killer and that she was his thirteenth victim, and said she would never be found.
A cadaver dog detected the scent of human remains in the bathroom of Christensen's apartment. In spite of efforts to clean the bedroom with bleach and Drano, police found blood matching Zhang's DNA on the underside of the carpet underneath Christensen's bed, behind the baseboard of the bedroom wall, and on the mattress. They also found a baseball bat stained with Zhang's blood.
At Christensen's trial in June 2019, his defense admitted he'd killed Zhang, but disagreed with the prosecution as to how and why he did it. The FBI was unable to link Christensen to any unsolved crimes in spite of his claim of being a serial killer. His defense argued he was drunk when he made the recorded confession of murder to his girlfriend, and that he suffered from mental illness and should not be executed.
Christensen was convicted of murder. The prosecution had sought the death penalty, something Zhang's family also wanted, but the jury could not unanimously agree on what Christensen's sentence should be, so the judge sentenced him to life in prison.
Foul play is suspected in Zhang's case due to the circumstances involved.