PEORIA — In the weeks after Yingying Zhang went missing, FBI agents and University of Illinois police officers searched through garbage at Centennial Park, an isolated area near Olympian Road and Interstate 57 and at the Murdock Mine 30 miles south of Champaign.
They went there based on tips and pings from Christensen's phone, but repeatedly came up empty.
"We were doing everything we could to try to determine where Yingying was," FBI agent Joel Smith testified Thursday, the second day of the prosecution's case against Brendt Christensen.
Smith described an exhausting and exhaustive search, with the FBI brought on to assist UI police and eventually calling on its Springfield office for backup.
At Centennial Park, the garbage cans go 6 feet deep into the ground, so the FBI had the Champaign Park District use its equipment to lift them out, and Smith said he cut each of the 14 liners open with a knife but found nothing.
Near I-57, they searched for two hours but found nothing, Smith said.
They interviewed multiple sexual partners of Christensen, Smith said, but learned nothing useful to finding Ms. Zhang.
The FBI was called in three days after Ms. Zhang went missing June 9, 2017. UI police had identified her getting into a black Saturn Astra, but agents were getting exhausted.
"They were working with minimal rest," FBI agent Anthony Manganaro testified Wednesday.
In the first three weeks of the search, they were working 20-hour days, Smith said.
Manganaro was called into the case by his supervisor, who was on his first day on the job and made Manganaro the point person on this case.
Manganaro said there was a level of desperation among UI police, especially since they didn't know where the car in the video went.
When Smith went to Christensen's apartment looking for local Astra owners, Christensen said he might have been sleeping or playing video games, Smith said.
He mostly appeared normal, Smith said, but his fingers were shaking when he checked his phone for text messages from June 9, and when Smith's partner searched the Astra's glovebox, Christensen broke eye contact with Smith for a few seconds.
Two days later, a UI police officer noticed a crack in the right front hubcap of the Astra and a sunroof, which matched Christensen's Astra.
That night, they tracked down U.S. Magistrate Judge Eric Long at a park, who was there for his daughter's event, and he signed a search warrant for Christensen's car.
They lined up a tow truck and executed the search warrant that night, interviewing Christensen at an FBI field office less than a mile away from his apartment.
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At Wednesday's hearing, prosecutors played the nearly hour-long interview with UI police Officer Eric Stiverson, Manganaro and Christensen.
During the interview, Christensen tried to stick to his initial story of playing video games and napping.
"We know that's not true," Stiverson said.
"Why would I lie?" Christensen responded.
Stiverson explained that there was extensive video surveillance around campus.
"I've seen the videos, but I didn't see me," Christensen said.
Stiverson said he saw his arms fully extended and asked, "Where'd you drop her off?"
At this point, Christensen started to sound nervous and replied, "Maybe I'm getting my days mixed up then. I thought I drove around Saturday. I did pick a girl up" who spoke broken English in the early afternoon.
He said he let her out a couple blocks away after he apparently made a wrong turn.
Then he said he went home.
"That was enough for me that day," Christensen said.
He was driving around, "just trying to clear my head, more or less," because his wife was away that weekend with her new boyfriend in Wisconsin.
Manganaro said he didn't think he let her out and asked Christensen if he was trying to hook up with the girl he picked up.
"That would've been nice," Christensen said.
But he insisted he didn't have sex with her and that he let her out a few blocks away.
Stiverson let him know they can track phones.
"I know you didn't drop her off in that neighborhood," he said.
"Where'd you take her?" Manganaro demanded. "We need to find Yingying."
"I think it's time that I stopped answering questions," Christensen said, ending the interview.
At this point in the trial Thursday, the court took a lunch break, and when the proceedings resumed, Assistant Federal Defender George Taseff called for a mistrial because the prosecution had played portions of the video showing Christensen invoking his rights.
"This is terribly prejudicial to this man," he said.
U.S. District Judge Jim Shadid asked why this concern wasn't raised earlier and how it was relevant, given the defense's opening statement, in which they admitted Christensen killed Ms. Zhang.
He asked whether it would effect whether the jury would find Christensen guilty.
"It very well could," Taseff said, noting that they have a duty to raise issues as they see them arise.
Shadid denied the motion, and Manganaro's testimony continued.
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Manganaro explained the various Google searches Christensen had made from the day before Ms. Zhang went missing to the day he was arrested three weeks later.
On June 8, he searched for "OxiClean and laundry."
Three days after he abducted Ms. Zhang, he searched "how iPhone tracking works."
Five days later, he visited the UI police website on the search for Ms. Zhang, which he would repeatedly visit over the coming days, and a News-Gazette article on the FBI's $10,000 reward for information leading to Ms. Zhang's location.
In the following days, he visited the Wikipedia page about the search, the family's GoFundMe fundraising page and international news articles on the search.
On June 20, he searched "obstruction of justice" and "obstruction of justice illinois penalty."
On June 27, he visited The News-Gazette's article on an upcoming campus vigil for Ms. Zhang multiple times, and then multiple articles about the FBI announcing they'd located the Astra.
On the day of the vigil two days later, he visited The News-Gazette article about it four times.
The following day, he checked the UI police's search page at 10:19 a.m. and again at 12:05 p.m.
He was arrested later that day, his 28th birthday.
During cross-examination, Assistant Federal Defender Elisabeth Pollock questioned the prosecution's timeline of events the morning of Ms. Zhang's kidnapping.
After he went to Schnucks and quickly bought a bottle of Admiral Nelson spiced rum for $17.99 at 7:51 a.m., his car was seen on campus surveillance footage beginning at 8:22 a.m.
In that time, the prosecution said in its opening statement, he went home and shaved.
Asked whether Christensen would've been able to both shave and cross town during "rush hour" in 30 minutes, Manganaro admitted it "might have been tight."
Pollock also questioned the relevance of Manganaro's testimony about Christensen buying a 6-foot green duffle bag six days before Ms. Zhang was abducted.
The FBI bought one of its own, and Manganaro held it up for the jurors to see. It appeared to be taller than him, and certainly taller than Ms. Zhang, who was 5-foot-4.
But Pollock said that Christensen's wife had seen that bag in their apartment three days after he killed Ms. Zhang.
She saw him carry the bag out without difficulty and didn't notice anything out of the ordinary, Pollock said. No smells or stains.
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Pollock also questioned Manganaro about the FBI's search for Christensen's 13 alleged victims, which he is heard saying on a wire recording his girlfriend made, trying to establish that Christensen's statements into the wire can't be trusted.
Manganaro confirmed that they checked his criminal history and found nothing and checked his DNA with a database and found nothing.
Pollock also said they checked his financial history, texts and social-media history but couldn't find anything.
Manganaro said it was a difficult search, because they didn't have any names of the purported victims.
In response, Assistant U.S. Attorney Bryan Freres asked if the FBI knew where Christensen had been every minute of his life.
They did not, Manganaro said.
And Freres asked if the FBI always found everyone on their missing persons list.
They did not, Manganaro said.
That finished up questioning Thursday, the second day of Christensen's trial, where he faces the death penalty if convicted.
The prosecution will continue calling witnesses today and is expected to play the incriminating wire recordings Christensen's girlfriend made of Christensen at the campus vigil.