FBI agents arrested Brendt Christensen last week. Agents say they placed him under surveillance and allege that they heard him boast about kidnapping the University of Illinois student.
On Monday, a large crowd stood outside and in the lobby of the federal courthouse in Urbana, Illinois, holding signs calling for justice for Zhang. Inside, the courtroom was filled with students and community members.
The case has shaken staff and students at Illinois' flagship public school in Urbana-Champaign. And some parents of the more than 300,000 Chinese students studying at American universities are asking whether it's safe send to their children to the United States.
Christensen said nothing at the brief hearing other than responding "yes," when the judge asked him if he understood his rights.
His attorney reminded reporters that his client is innocent until proven guilty. “There's a lot the public doesn't know,” he said.
Federal authorities say they believe Zhang is dead, but have not found her body.
Zhang came to the University of Illinois in Urbana-Champaign for a year-long position as a scholar in the department of nature resources and environmental sciences just two months ago. A graduate student from China, Zhang's research focused on crop production.
Investigators say she disappeared June 9 while running late for an appointment to sign a lease on her apartment. Surveillance video at the bus stop shows Zhang waiting at a bus stop. A car pulls up, and Zhang enters the passenger side of the vehicle.
Police say no one has reported seeing her since.
Authorities suspected Christensen because his car matched the car in the surveillance video, including a sunroof and minor damage to a front hubcap.
Investigators also say Christensen has given more than one account of his whereabouts around the time of Zhang's disappearance. The suspect first said he could not remember what he was doing at the time that Zhang disappeared, and later said he picked her up in his car and dropped her off a few blocks away.
Police say Christensen visited a webpage on FetLife.com that discusses kidnapping.
News about Zhang's disappearance encouraged groups on the university's campus like the Chinese Students and Scholars Association to help by distributing fliers and spending time with Zhang's family.
"We definitely feel the emotions and the pain from the family. It only makes us want to help them more," Robin Huang, the group's vice president of public relations said to the News-Gazette.
Chinese media have covered Zhang's disappearance, with her friends and acquaintances drawing attention to her case on Chinese social media sites such as WeChat.
"There's so little we can do at home, but we'd like the local police in the United States to stay on top of the case and not to let it slide," said Zhao Kaiyun, a roommate of Zhang's at Peking University Shenzhen Graduate School. Zhang graduated last year with a masters' degree in environmental engineering.
University of Illinois representatives held a scheduled orientation session in China recently for students headed to the school and their parents. Several attendees asked about Zhang's disappearance, said Robin Kaler, the associate chancellor for public affairs.
"Parents were very concerned," she said. "We obviously tell them that it is a very safe community in general, but that there are instances when horrible things can happen. And this is one instance."
Urbana-Champaign, with a population around 250,000, typically records no more than a few homicides each year.
The university's reputation as a leader in agriculture studies attracted Zhang to the school. She was researching crop photosynthesis, Kaler said. She was expected to begin work on her Ph.D. in the fall.
Her boyfriend said Zhang was motivated to succeed by wanting to help her parents in Nanping, a city in a picturesque part of China amid mountain ranges and forests. She used part of her research income to buy her parents devices to make their lives easier, including a microwave and a cellphone, he said.
He and her father described Zhang as bright and studious, fun-loving and outgoing. She plays the guitar and was the lead singer in band called "Cute Horse" at college in China. One of her favorite songs, her boyfriend said, was "The Rose," a hit in 1980 for American singer Bette Midler.
Hosting about 5,600 Chinese students of 11,000 international students, the University of Illinois has the largest Chinese student population of any U.S. college. Nationwide, there are around 300,000 Chinese students enrolled in a U.S. university, according to government data.
Zhang's father, Ronggao Zhang, is in the U.S. from China, helping search for his daughter.
He had a message for whoever might have abducted her.
"We will forgive you," he said in a telephone interview. "But please, let Yingying go."
The 53-year-old, speaking through a translator, had a message for his daughter, too.
"Yingying, please be strong."
Associated Press contributed to this story.
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