This 2016 selfie photo provided by her family shows Zhang Yingying in a cap and gown for her graduate degree in environmental engineering from Peking University Shenzhen Graduate School. Photo: AP
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https://scmp.com/news/world/united-states-canada/article/2132685/suspect-kidnap-and-killing-zhang-yingying-may-blame United States & Canada
Suspect in kidnap and killing of Zhang Yingying may blame his mother’s pregnancy diet, court filings reveal
Brendt Christensen’s lawyers say the nutrition he received in the womb is relevant to their client’s complex case, as they seek to delay trial and oust judge
This photo provided by the Macon County Sheriff's Office in Decatur, Illinois, shows Brendt Christensen, who is accused of kidnapping and killing Zhang Yingying. Photo: AP
Lawyers for a former physics student accused of kidnapping and murdering Zhang Yingying, a 26-year-old University of Illinois scholar from China, may use details of his mother’s pregnancy diet to help argue their client’s case, newly filed public records reveal.
They also say they want the judge overseeing the death-penalty case to recuse himself, though they don’t spell out why.
In documents filed Wednesday in federal court in central Illinois, Brendt Christensen’s lawyers argue the case is so complex that they’ll need until June 2019 to prepare for trial, including to potentially research their 28-year-old client’s genealogy and prenatal care. Prosecutors want a trial much sooner, in October.
Fearful Chinese parents rethink sending children abroad after scholar’s kidnapping in US
Both sides agreed a scheduled February 24 trial date had to be struck after prosecutors announced in January they’ll seek the death penalty, citing allegations Christensen tortured Zhang before killing her. Capital punishment is available in federal cases – but rarely sought. The state of Illinois abolished the death penalty in 2011.
The defence must go through voluminous evidence, with less manpower than federal prosecutors have available. That includes thousands of written documents, 14 discs of wiretapped calls, a DNA report and hundreds of hours of phone calls recorded from Christensen’s jail. There also is data from seven computer hard drives and four cellphones, according to the defence.
The two-page filing informing US District Judge Colin Stirling Bruce that Christensen’s legal team wants him off the case asks for permission to file a formal motion of recusal under seal. It hints that previously sealed documents the defence tried but failed to get access to underlie the recusal request. It doesn’t say how. 
Zhang Ronggao, left, and Ye Lifeng display a photo them with their missing daughter, Zhang Yingying. Photo: AP
People react at a bond hearing for Brendt Christensen outside a courthouse in Urbana, Illinois, last July. Photo: TNS
Zhang’s disappearance on June 9 on her way to sign an apartment lease off campus in Urbana drew international media attention. The daughter of a semi-trailer driver in China had just missed a bus when Christensen lured her into his car, prosecutors say. Her body has never been found.
Prosecutors agree there’s a new layer of complexity now it’s a death-penalty case. In a Wednesday filing requesting an October 16 trial date, prosecutors estimated trial testimony should last two weeks, while any death-penalty phase could last for three weeks.
If jurors convict Christensen, prosecutor would portray the crime as calculated and cruel in seeking death. Defence lawyers would try to introduce mitigating factors, which can include evidence of mental illness or a difficult upbringing. 
Zhang Yingyin. Photo: TNS
The scope of the effort to save his life would involve a “comprehensive collection and analysis of every record that exists concerning the defendant,” defence filings say. A “multigenerational investigation of (Christensen’s) family tree” and research into nutrition he received while in his mother’s womb could offer insight into his mental state, the defence argues.
They cite New York psychiatric epidemiologist David Freedman as saying: “Even such common events as preterm birth and low birthweight … are associated with later psychiatric and medical illnesses.”