FILE - Brendt Christensen was convicted of the kidnapping, raping and stabbing of visiting University of Illinois Chinese scholar Yingying Zhang.
FILE - Brendt Christensen was convicted of the kidnapping, raping and stabbing of visiting University of Illinois Chinese scholar Yingying Zhang.

PEORIA, ILLINOIS - U.S. prosecutors argued on Monday that an Illinois man who kidnapped, raped and murdered a Chinese graduate student two years ago should be executed, telling a jury that his crime was one of "calculated" cruelty.

The federal jury in Peoria, Illinois, that found Brendt Christensen, 29, guilty last month of the abduction and murder of Yingying Zhang, a 26-year-old student at the University of Illinois at Urbana-Champaign, is now hearing the penalty phase of the trial.

"This was not an ordinary crime," James Nelson, a prosecutor in the U.S. Department of Justice's capital case division, told the jury. "It was cold, cruel and calculated."

Christensen's lawyers have asked the jury to spare his life, saying he had long struggled with substance abuse and mental illness and had a family history of both.

FILE - Ronggao Zhang, left, and Lifeng Ye, display a photo of themselves with their missing daughter, Yingying Zhang, in Urbana, Ill., Nov. 1, 2017.

"No one who grew up with Brendt would have ever guessed that this is how his life would end up," Julie Brain, one of his lawyers, told the jury. "This was a man secretly struggling with mental health his whole life."

She showed the jury photographs of Christensen in his youth dressed in his Boy Scouts uniform and his football uniform.

The jury is being asked to decide between the death penalty and life in prison without the possibility of parole. 

Federal prosecutors are seeking the death penalty under U.S. kidnapping laws.

Appeal to Trump

Zhang was reported missing on June 9, 2017, two months after coming from southeastern China to study photosynthesis and crop production at the university. Her remains have never been found, but prosecutors said her DNA was matched to blood later found in three spots inside Christensen's bedroom.

The case has been closely watched by China's media and government as well as by Chinese students in the United States. 

Zhang's relatives publicly appealed to President Donald Trump for additional resources to help find her two months after she vanished.

Details of the crime

Investigators were led to Christensen through surveillance video footage captured in Urbana, 130 miles (210 km) south of Chicago, that showed Zhang getting into a black car that later was traced to Christensen.

Prosecutors said Christensen, a one-time master's student at the university, took Zhang to his apartment, where she fought for her life as he bludgeoned her with a baseball bat, raped her and stabbed her in the neck before cutting off her head.

Earlier in the trial in U.S. District Court in Peoria, prosecutors characterized Christensen as having a fascination with serial killers, including Ted Bundy, who murdered dozens of women during the 1970s and was put to death in 1989.

Details of the crime, including Zhang's decapitation, were revealed by Christensen himself in conversations with his then-girlfriend secretly recorded for FBI agents investigating the case before his arrest, according to trial testimony.