EMBED >More News Videos The mystery woman who attended a vigil with the suspect charged in the kidnapping and death of U of I visiting scholar Yingying Zhang.

EMBED >More News Videos University of Illinois police are credited with the detective work that lead authorities to the suspect.

EMBED >More News Videos In a court hearing, prosecutors revealed what was in the secret recordings the FBI made of Brendt Christensen.

EMBED >More News Videos U of I spokesperson Robin Kaler on the additional security measures in place after Yingying Zhang's disappearance.

EMBED >More News Videos ABC7 legal analyst Gil Soffer explains the Federal Kidnapping Act, popularly known as the Lindbergh Law.

EMBED >More News Videos ABC7 legal analyst Gil Soffer on the death penalty.

CHAMPAIGN, Ill. (WLS) -- A visiting University of Illinois scholar from China disappeared and is presumed dead. The man accused of kidnapping her is in jail. But the I-Team has found that is just the beginning of a mystery spanning the globe from Illinois to East Asia.In what investigators believe to be a brazen move by suspected killer Brendt Christensen, the U of I doctoral student actually attended a vigil for Yingying Zhang, the Chinese student he is charged with kidnapping. Christensen is seen in pictures with a mysterious woman and he was arrested the next day after allegedly admitting on a recording how he kidnapped Zhang, brought her back to his apartment and held her against her will.Her body has not been found. New federal charges mean the former Ph.D. student could face the death penalty.The tragedy began on June 9th after Yingying Zhang missed the bus on her way to sign an apartment lease.The Friday Zhang disappeared was a typical one for the visiting scholar. Police say she spent the morning doing research at Turner Hall and then went back to her apartment at Orchard Downs for lunch. She then left on a bus for an appointment to sign a new lease at a different apartment complex in Urbana. She tried flagging down a connecting bus but it did not stop. Zhang walked north to another bus stop nearby. That is when police say Brendt Christensen pulled up in his car and, after a brief conversation, Zhang got into the passenger seat. Zhang never showed up for her appointment at One North Apartments.University of Illinois police are credited with aggressive detective work that lead authorities to suspect Brendt Christensen.During a detention hearing on July 5, 2017, prosecutors revealed what is on the secret FBI recordings.New security training in China will begin next year for the thousands of students coming from there to the Champaign-Urbana campus.Nearly 6,000 students from China are enrolled at the University of Illinois. That's more than any other U.S. college.Kidnapping cases are usually charged by the state. ABC 7 legal analyst Gil Soffer explains why suspect Brendt Christensen is charged in federal court.Brendt Christensen could face the death penalty if approved by the U.S. attorney general.