Korea introduced jury trials in 2008 to promote citizen participation in the judicial process. Under the system, lay citizens serve as jurors in criminal trials. They are given the power to decide on the facts, deliver a guilty or not-guilty verdict, and present opinions on what the punishment should be.

In the Korean system, a defendant is given the choice over whether to request a jury trial. In 2008, 233 defendants chose to be tried through the new procedure. The figure rose to 437 in 2010 and 737 last year. The rapid increase suggests bright prospects for the judicial experiment in Korea.

Yet the participatory trial system is still in an experimental stage. Unlike in the United States, jury verdicts are not binding here. And jury trials are only applied to criminal cases, not civil ones.

To help the new system take root, the Supreme Court expanded last year the scope of the cases eligible for a jury trial. Initially, only certain categories of criminal cases were eligible. Now, all criminal cases under jurisdiction of a collegiate panel are.

The top court also seeks to make the jury verdict binding. In March it proposed a bill requiring judges to follow jury verdicts as long as jurors have not breached the Constitution or any other law in the process of deliberating on their cases.

Yet before going any further, the court needs to think about the wisdom of applying the participatory trial system to political cases. In a country where politics is driven largely by regional antagonism, jurors are often swayed by regional sentiments when they deal with political cases.

A case in point is the ongoing trial on poet Ahn Do-hyun, who was indicted for spreading groundless rumors against Park Geun-hye during the presidential election last year. At the time he was a co-chairman of the campaign headquarters for opposition candidate Moon Jae-in.

On Monday, the seven-member jury at the district court in Jeonju reached a unanimous non-guilty verdict. But the panel of judges disagreed with it and decided to delay the sentencing. They said, “We respect the jury’s view. But we must mete out justice in accordance with the Constitution and the law.”

The problem lies in the composition of the jury. The law requires a court to select jurors from among the residents of the region within its jurisdiction. So the seven jurors are all from North Jeolla Province.

In the December presidential poll, more than 85 percent of the province’s voters supported Moon. This suggests that if you pick seven jurors from among people there, six are Moon supporters.

In such a region, it is difficult to expect jurors participating in a political case to reach a conclusion based on reason and logic. Before them comes regional bias. This problem is not limited to North Jeolla Province. In the Yeongnam area, the bastion of the conservative Saenuri Party, juries are likely to consist of Park supporters.

This raises the possibility of courts in different regions coming up with widely different jury verdicts on similar cases, thus causing confusion and eroding consistency of adjudication.

The top court needs to address this problem before taking further steps to strengthen and expand the participatory trial system. It may have to readjust the scope of cases eligible for a jury trial.