CHICAGO, June 13 (Xinhua) -- Testimony continued Thursday at a federal courthouse in Peoria, U.S. state of Illinois, for the trial of Brendt Christensen, who is accused of kidnapping and killing Chinese visiting scholar Zhang Yingying in 2017.

The testimony of the trial started from 9 a.m. (1400 GMT), after Zhang's boyfriend and local police testified in the previous day.

Zhang's father, younger brother and boyfriend stayed in the courtroom, listening to a translation of proceedings on headphones. Zhang's mother, too emotional to be in court, watched from overflow room with translators.

The jury heard testimony Thursday morning from Joel Smith, an FBI Agent, who was involved in the initial days of the investigation.

Smith described the initial searches of Christensen's apartment and vehicle.

Smith said Christensen was narrowed down as a person of interest from a list of owners of Saturn Astras. The vehicle was seen on surveillance video picking up Zhang.

It's not a very common vehicle, and Christensen's Saturn had a sunroof and a cracked hub cap, which were seen in the video. That's how he initially became a suspect.

Another FBI agent Anthony Manganaro testified that he went through Christensen's google searches from June 8 to June 30.

Among the findings are a June 8 google about Oxiclean, a household stain remover, a June 12 google "how iPhone tracking works;" and googles for campus police department's search update and the News-Gazette article on 10,000 U.S. dollars reward on June 17.

On Wednesday, one of Christensen's attorneys admitted in the court that the defendant indeed kidnapped and killed Zhang.

Zhang, a 26-year-old visiting Chinese scholar at the University of Illinois at Urbana-Champaign (UIUC), 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.

Police arrested Christensen on June 30, 2017, who was a former UIUC doctoral student, and charged him with the kidnapping, torturing and killing of Zhang. He pleaded not guilty.