East Baton Rouge Parish is putting all jury trials on hold — perhaps into June — after the state Supreme Court declared Thursday that the parish's jury pool was so flawed that a Shreveport judge must start over from an entirely new jury pool in the capital murder trial of accused cop-killer Grover Cannon.

After lawyers and Caddo District Judge Ramona Emanuel had traveled to Baton Rouge last month to begin selecting jurors and alternates, Cannon's defense team discovered that none of the 566 potential jurors summoned was under age 26.

A further review of parish jury pool records found that no one born after June 2, 1993, had ever been called to jury service in the parish, due to a computer “glitch” that rejected periodic updates.

The flaw left the jury pool essentially the same since 2011, as even people who moved to East Baton Rouge since then were never added, 19th Judicial District Court Administrator Ann McCrory testified at a hearing last week.

After justices decided Thursday that Emanuel could not proceed with such a limited jury pool, East Baton Rouge Parish District Attorney Hillar Moore III said all jury trials set in the parish will be put on hold until a new jury pool is in place, likely in early June.

"That is the earliest they can get it ready," Moore said. "It obviously sets us back."

He said he couldn't immediately say how many trials might be affected since many defendants plead guilty right before trial. Moore also said his office would not oppose any defense motion to continue a trial until a new pool is ready.

Many trials, including Cannon's, may be delayed still longer, Moore said, depending on the judges' schedules. Judges in the 19th JDC only allot certain weeks for trials.

In its one-page opinion Thursday, the Supreme Court said Emanuel could not use the East Baton Rouge jury pool, calling it "improperly constituted" under two articles of the Louisiana Constitution — the right to equal protection under the law, and the right of adult citizens to serve as parish jurors.

The ruling wiped out nearly three weeks' worth of jury selection.

Justice Greg Guidry issued a separate, concurring opinion that made clear he didn’t think the constitution required throwing out the jury “venire,” but that it was warranted “both out of an abundance of caution and to prevent a possible waste of judicial resources.”

The decision arrived as a rebuke to Emanuel, who had pressed forward with the elaborate jury selection process required for death penalty trials, denying repeated requests by Cannon's defense team to suspend the trial given evidence that a whole swath of the populace was left off the rolls.

Cannon is accused of killing Thomas LaValley as the Shreveport police officer responded to a domestic call. Pretrial publicity pushed the trial to East Baton Rouge Parish, but only for jury selection. The chosen jurors and alternates will travel to Shreveport to weigh Cannon’s fate at a trial there.

Moore said it wasn't clear whether the outside vendor for the court's jury system had isolated the computer problem that caused the jury pool list to remain stagnant for years. McCrory, the court's administrator, did not immediately return a request for comment. East Baton Rouge Parish court offices were closed Thursday because of bad weather.

Dwight Doskey, Cannon’s lead defense attorney, said the decision will put on hold “any prospective case until they manage to correct their system.”

He said he expected that jury officials would need at least six weeks to install a new jury pool and send out questionnaires, the first stage to creating a group of a few hundred randomly selected people needed for a capital trial.

Not answered is whether people already convicted by juries that were chosen from the outdated pool hold a valid claim that their guilty verdicts must also be tossed out.

“I do not know the result as to people who are filing to vacate their convictions,” Doskey said.

About 34 jury trials a year were held in the 19th Judicial District, on average, over the six-year period ending in 2016. Nearly all of them took place during the time frame in which jury officials acknowledge the parish jury list was growing ever more stale.

Chris Aberle, director of the Louisiana Appellate Project, which handles appeals for indigent defendants, said he expects challenges to previous convictions but hadn’t assessed the ruling's impact.

Mike Mitchell, public defender in East Baton Rouge Parish, said he also expects numerous legal challenges based on the court’s decision Thursday. “I believe every case that was tried under this system will likely be challenged,” Mitchell said.

Staff writer Bryn Stole contributed to this story.

Follow John Simerman on Twitter, @johnsimerman.