CHICAGO — The first day of testimony in the criminal trial of former “Empire” actor Jussie Smollett concluded Tuesday after the lead detective in the case spent more than eight hours on the witness stand.

Michael Theis, now the assistant director of the Chicago Police Department’s Research and Development Division, was the primary investigator when Smollett reported to police that he was the victim of a hate crime in Streeterville on a frigid night in January 2019.

Theis, while being questioned by attorney Samuel Mendenhall of the special prosecutor’s office, said that police spent thousands of collective hours analyzing surveillance footage, cellphone data, social media activity and other investigative avenues before they concluded that Smollett faked the attack.

“At the end of our investigation we determined that the alleged hate crime was actually a staged event and that it did not occur,” Theis said.

Mendenhall asked Theis why the CPD would devote so many resources to the case.

“This was horrible,” Theis added. “The crime was a hate crime but a horrible hate crime. There was a noose, there was bleach…Everybody wanted to know what happened. From the mayor on down, everybody wanted answers.”

Smollett, 39, was charged last year with six counts of disorderly conduct for reporting an allegedly phony hate crime to police, allegedly after he was dissatisfied with the “Empire” studio’s response to a hate letter — targeting Smollett — that it previously received.

Prosecutors alleged that Smollett employed two bodybuilding brothers — Olabinjo and Abimbola Osundairo — who were extras on “Empire” to help him stage the attack.

Nenye Uche, one of Smollett’s attorneys, sought to demonstrate that the Osundairo brothers harbored homophobic feelings and targeted Smollett because he is gay.

At one point, Uche pointed to a tweet from Olabinjo Osundairo in which he criticized another Twitter user for following the singer Frank Ocean, who identifies as bisexual.

Uche’s questions were frequently objected to by Mendenhall, and Cook County Judge James Linn called several sidebars with the attorneys in an effort to keep the questioning of Theis in line with court rules.

“You’re just trying to be a good lawyer, and I get that,” Linn told Uche after the jury left the courtroom. “Don’t argue with the court. Just ask the questions, please.”

The Osundairo brothers are both expected to testify later this week.

The special prosecutor’s office, led by former U.S. Attorney Dan Webb, also highlighted Smollett’s refusal to fully cooperate with police after the hate crime was initially reported. Smollett declined to share with detectives his cellphone data, his DNA and medical records, Theis testified.

After Theis’ testimony concluded, the special prosecutor’s office called CPD officer Muhammad Baig to testify. Baig was one of the first two officers to respond to Smollett’s hate crime report.

Baig said that, upon his arrival at Smollett’s Streeterville apartment, Smollett still had a rope around his neck. Earlier in the day, Mendenhall noted that Smollett was initially resistant to calling police, and officers did not arrive at his home until more than 30 minutes after the alleged attack.

“With no explanation, Mr. Smollett kept on a vicious symbol of hate,” Mendenhall said.

As Baig testified, Mendenhall played for the jurors a copy of the bodyworn camera footage that Baig recorded while responding to Smollett’s home. In the video, Smollett can be seen in his home with a rope around his neck. Baig then asks Smollett if he’d like to remove the rope.

“He responded by saying that he wanted to take it off, but he wanted us to see it first,” Baig testified.

The trial is set to resume Wednesday morning and is expected to last at least through the end of the week.