A convicted felon walked into an Indianapolis sporting goods store with a friend in December 2011. In the presence of a store employee, the felon pointed out the handgun he wanted, and the friend purchased it for him a few hours later, a lawsuit alleges.

Two months later, the felon, Demetrious Martin, used the handgun to shoot Dwayne Runnels, an Indianapolis Metropolitan Police Department officer who was on duty, court documents say. Runnels returned fire, killing Martin.

Now, Runnels wants to hold KS&E Sports, the sporting goods store, responsible for what he alleges was an illegal straw sale that led to his shooting.

But because of an Indiana law, he might not be able to.

The question of whether a gun seller can be held liable for criminal misuse of a gun — when the seller has acted illegally — is at the center of a lawsuit filed by Runnels in 2013. Indiana law gives immunity in civil cases to sellers and manufacturers when a gun is used to commit a crime by a third party. But the law doesn’t spell out whether the immunity protects sellers if they illegally sell a gun to a person who uses it to commit a crime.

The case centers on civil liability and whether companies should have to pay out damages. A gun seller who is proved to have made an illegal sale can face criminal punishment.

The Indiana Supreme Court on Wednesday heard oral arguments in the case after the Indiana Court of Appeals in March ruled that the sporting goods store is not immune from a lawsuit in this case because of the allegation that the store was complicit in an illegal straw sale. In other words, the court said that Runnels should be able to proceed with the lawsuit to try to prove his claims.

Attorneys for KS&E Sports in 2014 asked a Marion Superior Court judge to throw out the case, arguing that the state’s immunity statute means the sporting goods store was not responsible for Martin’s actions when he shot Runnels. The judge, though, ruled in favor of Runnels, allowing the suit to go forward. The Appeals Court ultimately agreed.

Now, the state’s highest court will soon make a decision that could have implications for such cases. If the court rules in favor of Runnels, it could highlight an exception to Indiana’s immunity statute that could make a gun seller liable for civil damages if a plaintiff can prove the seller acted illegally. If the court rules against Runnels, it could strengthen the immunity law, making it more difficult to successfully sue a seller or manufacturer.

Jonathan Lowy, an attorney for Runnels, contended in oral arguments that the Indiana General Assembly did not explicitly write that sellers have immunity in cases involving their own illegal actions. He also noted that such an interpretation of the immunity statute would be out of step with other Indiana laws, which rarely grant such broad immunity in all circumstances.

“Even good Samaritans don’t get immunity if they engage in gross negligence,” argued Lowy, who is an attorney for the Washington, D.C.-based Brady Campaign to Prevent Gun Violence.

Yet Supreme Court Justice Mark Massa questioned whether the gun seller could be held responsible for damages stemming from an act that hadn’t occurred yet. In Runnels’ case, Martin hadn’t injured him at the time the handgun was purchased.

“At the moment the transaction takes place, there are no damages unless and until a third party criminally misuses a firearm,” Massa said.

Christopher Renzulli, an attorney for the sporting goods store, argued that the law written by the General Assembly intended to stop lawsuits that target gun sellers based on criminal actions of a third party. He said the legislature didn’t specify that the sale had to be a legal sale and noted that gun sellers can still face criminal punishments for illegal sales.

“The General Assembly felt that we are not going to get involved parsing through every sale of a firearm — should they have known this was a straw sale? Should they not have known this was a straw sale?” Renzulli said.

Questioning Renzulli, Justices Stephen David and Robert Rucker presented him with a hypothetical: What if a man who is a convicted felon and on a terrorist watch list walked into a gun store with a companion who purchased a gun for him, while they discussed using the gun for nefarious purposes?

“He goes to a school and wreaks havoc. Is it your position that there is no civil liability?” Rucker asked Renzulli.

Renzulli replied that there would not be any liability in that case.

Renzulli and Lowy declined to comment after the hearing, saying they will await the court’s ruling.

The immunity statute has been used to try to halt lawsuits that target gun sellers and manufacturers. The General Assembly first enacted legislation to restrict lawsuits against gun sellers two years after the city of Gary sued Smith and Wesson Corp. in 1999, alleging negligence when selling its product, which the city claimed was responsible for violent crime in Gary streets.

The Indiana Court of Appeals in 2007 allowed the Gary case to proceed. It remains pending.

In 2015, the General Assembly tweaked the legislation in an attempt to further protect gun sellers. Lawmakers who supported the legislation said it would create jobs in the firearms industry. Opponents, though, said it favored the firearms industry over citizens.

Former IndyStar reporter Jill Disis contributed to this story.

Call IndyStar reporter Madeline Buckley at (317) 444-6083. Follow her on Twitter: @Mabuckley88.