PEORIA, Ill. (WAND)- Presentation of evidence in the Brendt Christensen trial ended Friday afternoon. 

Judge James Shadid asked Brendt Christensen if he planned to testify and advised him of his right to do so. Christensen said he would not testify. 

Earlier in the day, Brendt Christensen's ex-wife testified for the defense.

Michelle Zortman, 31, told jurors she and Christensen met in Stevens Point, Wisconsin while working at a Kmart. The two spent almost every night together while dating and during their marriage, she said.

While living in Madison and then Champaign, the two had very little social life and spent their time away from work or school watching TV and movies and playing video games. While studying in Madison, Christensen's drinking became heavier, she said.

"It began during winter and summer breaks; when he had unlimited time on his hands he would fill it with drinking," Zortman said. By 2016, Christensen began drinking excessively during school semesters in part because of sleep problems and marital problems, she said.

"His drinking was getting worse, along with other substances," Zortman said.

As their marriage deteriorated, a co-worker asked Zortman to begin a romantic relationship with him and ask Christensen for an open marriage. Christensen eventually agreed, she said.

In Spring 2017, Zortman and her boyfriend made plans to travel together to Wisconsin Dells on a long weekend. Zortman said Christensen seldom showed his emotions and initially did not seem upset by the plans, but she said Christensen became upset about the trip a few days before she left early June 9, 2017.

Defense attorney Elisabeth Pollock asked Zortman whether Christensen was drunk the night she picked him up after the memorial walk for Yingying Zhang. It was after that walk that Christensen was recorded describing violently killing Yingying Zhang, and Christensen's defense have tried to cast doubt on the truthfulness of that account.

"He was drunk," Zortman said. "He wasn't being serious."

In cross-examination, Zortman said that she filled up the couple's Saturn Astra with gasoline before leaving for Wisconsin. When she returned, the tank was half-full, she said. Prosecutors suggested using half of the 12 gallon tank would mean the car drove about 200 miles or drove about six hours in local traffic.

After Zortman returned from Wisconsin, Christensen pointed out at least one blood stain on their mattress and told her he had had a nosebleed, Zortman said. She had not seen the stain before the weekend away, Zortman said.

She also admitted that, in the weeks before her Wisconsin trip, Christensen had maintained his relationship with girlfriend Terra Bullis, had pursued other women and had had a one-night-stand.

Zortman said she still cares about Christensen.

"He was the biggest person in my life for a decade," she said. "It's difficult to cut ties."

Later, Christensen's defense played an uncut video recording of Christensen's visit to a University of Illinois counselor in April 2017. 

In a form filled out for the counseling session, Christensen had admitted to having thoughts of harming himself and harming others. 

When asked, Christensen told the counselor he had gone "pretty far" in planning to hurt someone else. He also described his interest in serial killers like Ted Bundy. 

"I've always been interested in the bad guys," Christensen said. "A few years ago, I happened on a forum about serial killers. When I was looking at that, it just fascinated me." 

In the video, the counselor can be seen going to her computer and typing a message asking someone else to come into the session for consultation, an FBI agent said when asked by Christensen's defense. No one came, and nine days later, Christensen returned to the counseling center and gave more detailed information about planning to hurt someone, he said. 

Earlier in the morning, Christensen's defense recalled FBI agent Anthony Manganaro  to the stand and called their own investigator Alan Polock to the stand to cast doubt on earlier testimony by Charles Hill, who was a Macon County jail inmate alongside Christensen.

Hill had testified earlier at trial that Christensen told him of having zip ties and of posing as a police officer with a badge and walkie-talkie. 

Closing arguments are expected Monday.