Courts confront betting markets that let users wager on jury outcomes

Judge credits defense concerns on jury contamination in Robinson case

The wagers on Clancy, Robinson and other criminal cases were available on an offshore platform run by Polymarket, which has also hosted bets on the federal prosecution of Sean “Diddy” Combs and the government’s current case against ousted Venezuelan President Nicolás Maduro. Many courts have not spent much time thinking about prediction markets yet, court staff say, but at least a handful are beginning to address the issue.

At least one federal court is already acting. The U.S. District Court in Chicago is updating its insider-trading policies to prohibit employees from using on-the-job information to make prediction wagers. Judges in the district are on alert for similar concerns that might arise in jury trials, said Sean Lewis, a court spokesman.

“As technology and society evolve, the court will continue to adapt its policies to safeguard the fair and impartial administration of justice,” Lewis said.

The most direct and obvious concern is the potential for jurors to bet on their own deliberations, creating financial incentives to reach particular outcomes no matter the facts of the case. Some court staffers are also potentially in positions to have inside knowledge of how deliberations are proceeding.

When the public treats a courtroom like a casino, due process is susceptible to corruption, said C. Melissa Owen, president of the National Association of Criminal Defense Lawyers.

The accessibility and pervasiveness of betting platforms makes the possibility of corrupting jurors a real risk, said University of Chicago law professor M. Todd Henderson. He said there is also a broader concern that prediction markets with heavy betting could influence how jurors think about a case — whether, for instance, millions wagered on the belief that a defendant will be acquitted could make a jury more reluctant to convict.

“For Joe Q Juror sitting at home,” Henderson said, “the question is: Is he likely to be more biased as a juror if he sees the odds on Polymarket than if he sees a pundit in the newspaper or on TV talking about what the chances are that Tyler Robinson did it?”

Robinson, accused of killing conservative commentator Charlie Kirk at a university event last year, has no trial date set yet. More than $300,000 had been wagered on the outcome of his case before Robinson formally entered a not guilty plea last month.

Robinson’s lawyers flagged the Polymarket bets to the presiding judge, arguing the wagering was a “morally dubious enterprise” that commodified death-penalty litigation. The defense said trading volume was active during a preliminary court hearing in July, and argued that continuing to broadcast the court proceedings would exacerbate the problem and create additional pretrial publicity that was unfair to Robinson.

“The Court credits Defendant’s concerns regarding jury contamination and prediction-market activity as genuine,” Judge Tony Graf wrote in a ruling last month. But he allowed continued livestreaming of the proceedings and suggested that any concerns could be addressed during jury selection, including by asking potential jurors about any exposure they had to prediction markets.

In Massachusetts, bettors wagered more than $100,000 on the verdict in the summer murder trial of Lindsay Clancy, who is accused of killing her children. Since a deadlocked jury forced a mistrial in early September, more than $500,000 in additional bets have been placed on whether Clancy will eventually be convicted.

One of the nation’s most prominent legal venues — the federal trial court in Manhattan — has attracted at least two notable betting markets. Between May and July of last year, Polymarket users bet nearly $798,000 on the verdict of the Combs sex trafficking trial. Combs was found not guilty of racketeering and sex-trafficking offenses but convicted of less serious charges.

Maduro is set to go on trial next year in the same court on charges including narco-terrorism. A Polymarket offering on whether Maduro will be found guilty has attracted about $133,000 in trading volume so far, while another on whether he will serve prison time has seen more than $900,000 of activity.

Typically, markets for betting on criminal cases have been hosted on offshore platforms because prediction-market companies have wanted to avoid running afoul of U.S. rules that prohibit gambling on sensitive topics including war, terrorism and assassination. Still, market observers say that accessing the offshore platforms isn’t difficult for domestic bettors.

Harry Crane, a Rutgers University statistics professor who serves on an advisory committee to the Commodity Futures Trading Commission, which regulates prediction markets, said around 20% to 40% of the money bet on offshore Polymarket markets comes from inside the U.S. The study doesn’t show whether that volume comes from many people making small bets or just a small number of super-users, Crane said.

A Polymarket spokesperson said people “trade on outcomes of real-world events including legal, political and economic developments. These markets do not impact the outcomes—they reflect what market participants collectively believe will happen.”

Polymarket has a data partnership with Dow Jones, the publisher of The Wall Street Journal.