Can Jason Van Dyke get a fair trial from a Cook County jury? The judge presiding over the case has decided to wait to answer that question until he talks to some prospective jurors.

After a marathon hearing Friday with testimony from jury experts hired by both the prosecution and the defense, Judge Vincent Gaughan said he won’t rule for now on a defense motion to move the trial, set to start Sept. 5, out of the county.

The hearing also featured a jury expert called by the defense showing a clip from Chicago rapper Vic Mensa’s “16 Shots.” The video includes grainy footage of Van Dyke shooting 16-year-old Laquan McDonald — and as of Friday, has been viewed about 1.7 million times on YouTube.

Seated a few feet away from the courtroom monitor screen, Van Dyke looked away from the video the entire time it played. The veteran officer looked on glumly for most of jury expert Bryan Edelman’s presentation, and grimaced as he stared at screens displaying quotes from social media postings on Facebook and news websites: “Liar and coward and killer,” one said.

Jason Van Dyke at a court hearing

Chicago Police Officer Jason Van Dyke looks at a video clip from the Blue Wall documentary is shown at the Leighton Criminal Courthouse Friday. | Antonio Perez/ Chicago Tribune/Pool photo

Edelman found more than 80 percent of the 399 Cook County residents he polled were familiar with the McDonald shooting, and 75 percent of potential jurors believed Van Dyke was guilty.

“In a big city, it takes a lot for a case to capture your attention,” Edelman said. “There’s a lot of powerful imagery out there.”

Gaughan, who presided over the high-profile trials of Chicago native R&B star R. Kelly and both defendants charged in the Brown’s Chicken massacre, seemed skeptical of the need to move the trial.

As Edelman wound up his more than two hours on the stand, the judge asked him whether asking probing questions of individual jurors — called “voir dire” in legal parlance — could reliably weed out bias.

“My experience with voir dire has been outstanding,” Gaughan said. “I believe in the jury process.”

The 2014 shooting, captured on dashboard camera video, became a flashpoint within the city, leading to protests that turned elections and prompted federal investigations of police tactics.

That notoriety is precisely why potential jurors are likely biased against Van Dyke, according to Edelman, who surveyed public opinion and media coverage in Cook County, neighboring Lake County and downstate Madison County.

Screenshot from video showing fatal shooting of Laquan McDonald

In this Oct. 20, 2014 file image taken from dash-cam video provided by the Chicago Police Department, Laquan McDonald (right) walks down the street moments before being fatally shot by Chicago Police officer Jason Van Dyke in Chicago.
| Chicago Police Department, distributed by the Associated Press

Prosecution expert Katharina Castaneda, who performed an online poll and some in-person interviews with county residents, found a lower percentage were convinced of Van Dyke’s guilt, and estimated there were 1 million possible jurors in Cook County who had no opinion about Van Dyke’s guilt or innocence.

Van Dyke’s defense team had filed a motion last week to have another judge decide the issue of where to locate the trial, claiming that Gaughan had already made up his mind not to move the case.

Taking a trial to another jurisdiction is a rare step in any case. Courthouse observers can recall only two instances, both decades ago, when a trial was either moved or jurors were brought in from outside the county: the 1967 trial of Richard Speck, which was held in Peoria; and the 1980 trial of John Wayne Gacy, in which jurors from the Rockford area were brought to Cook County.