CHICAGO, April 10 (Xinhua) -- Before allegedly kidnapping and killing visiting Chinese scholar Zhang Yingying in 2017, suspect Brendt Christensen already turned to University of Illinois Counseling Center for help with his suicidal and homicidal thoughts, according to documents unsealed this week.

In the defense motion, lawyers for the former University of Illinois (UI) student said university counselors didn't offer him adequate care when he sought help for suicidal and homicidal thoughts three months before Zhang Yingying went missing.

In the March 2017 interview at the UI counseling center, Christensen said he had been abusing alcohol and Vicodin, had expressed an interest in serial killers, and was depressed after dropping out of the physics Ph.D. program at the UI and because his wife proposed opening up their marriage of nine years.

In a bid to avoid the death penalty if he is convicted at his trial scheduled for June, Christensen's lawyers want to bring in an expert to argue that the UI could have done more to help Christensen by providing better follow-up care.

But at Monday's hearing in a federal court, which Christensen attended, Assistant U.S. Attorney Eugene Miller said prosecutors had an expert who believed the UI counseling center did what it was supposed to do, according to local media The News-Gazette.

Much of the discussion Monday was behind closed doors, so it's unclear if U.S. District Judge James Shadid has ruled on the motion.

Zhang, 26, went missing on June 9, 2017, after getting into a black Saturn Astra about five blocks from where she got off a bus on her way to an apartment complex to sign a lease.

Christensen was arrested on June 30, 2017, after being caught on tape pointing out people he described as "ideal victims" during a vigil in Zhang's honor. On July 5, U.S. Magistrate Judge Eric I. Long ordered that Christensen remain detained in the custody of the U.S. Marshals Service pending trial.