Sue Aitken called the police because she was worried about her son Brian. She now lives with the guilt of knowing her phone call is the reason Brian wound up sitting in a New Jersey prison. If it weren't for a commutation of his sentence from the governor's mansion, he would be stuck there for the next seven years.

Aitken was sentenced in August for felony possession of a handgun. Before his arrest, Aitken, the owner of a media consulting business, had no criminal record. By all appearances he made a good-faith effort to comply with the stringent New Jersey gun laws that eventually proved his undoing. Even the jurors who convicted him seem to have been looking for a reason to acquit Aitken. But the judge gave them little choice.

Aitken, born and raised in New Jersey, moved to Colorado several years ago. In Colorado he married the woman who is now his ex-wife, who was also originally from New Jersey. The two had a son together. When the marriage dissolved, Aitken's wife and infant son moved back to New Jersey. Aitken then also moved back to be closer to his son. Beginning in late 2008, he took the first of several trips between the two states, a process that involved selling his house in Colorado, moving his possessions across the country, and finding a job and new residence. Until he could find an apartment, he stored his belongings at his parents' home in Burlington County, New Jersey.

In December 2008, Aitken made a final trip back to Colorado to collect the last of his possessions, including three handguns he had legally purchased in Colorado—transactions that required him to pass a federal background check. Before leaving Colorado, Aitken researched and printed out New Jersey and federal gun laws to be sure he moved his firearms legally. Richard Gilbert, Aitken's trial attorney, says Aitken also called New Jersey State Police to get advice on how to legally transport his guns, although Burlington County Superior Court Judge James Morley didn't allow testimony about that phone call at Aitken's trial.

Aitken's legal troubles began in January 2009, when he drove to his parents' house to pick up some of his belongings. He had grown distraught over tensions with his ex-wife, who according to Aitken had refused to let him see his son. When Aitken visited his parents' house, his mother grew worried about his mental state and called 911. When police arrived at her home, Sue Aitken told them her concerns, and they called Brian, who was then en route to his new apartment in Hoboken, on his cell phone. They asked him to turn around and come back to his parents' house. He complied.

It was there that the police confronted Aitken. Although they determined he wasn't a threat to himself or anyone else, they searched his car, where they found his handguns—locked, unloaded, and stored in the trunk, as federal and New Jersey law require for guns in transport. The police arrested Aitken anyway, charging him with unlawful possession of a weapon.

New Jersey gun buyers must go through a laborious process to obtain a "purchaser's permit." But that permit doesn't allow you to possess a gun. A few select groups of people, mostly off-duty police officers and security personnel, can obtain carry permits. But anyone else with a gun is presumed to be violating state law and must defend himself by claiming one of the state's exemptions. The process effectively makes New Jersey gun owners guilty until they prove themselves innocent.

The exemptions allow New Jersey residents to have guns in their homes, while hunting or at a shooting range, while traveling to or from hunting grounds or a shooting range, and when traveling between residences. Aitken claimed he was moving between residences, and there is strong evidence he was. Sue Aitken testified that her son was moving his belongings from her house to his new home. So did Aitken's roommate. One of the police officers at the scene testified that Aitken's car was filled with personal belongings.

Yet Morley wouldn't allow Aitken to claim the exemption for transporting guns between residences. During deliberations, the jurors asked three times about exceptions to the law, which suggests they weren't comfortable convicting Aitken. The judge refused to answer all three times.

In response to a query about why Aitken wasn't granted the moving exception, the Burlington County Prosecutor's Office replied via email, "There was no evidence produced at the trial by the defendant that warranted such a defense." Gilbert, Aitken's lawyer, says that isn't true. "We put on plenty of evidence that Brian was moving," he says, "including testimony from his mother, his roommate, even the police officer who arrested him."

In a telephone interview, Morley (who lost his job when Gov. Chris Christie declined to reappoint him in June because of rulings in unrelated cases) says he didn't allow the jury to consider the moving exception because "it wasn't relevant." Morley adds: "There was no evidence that Mr. Aitken was moving. He was trying to argue that the law should give him this broad window extending over several weeks to justify driving around with guns in his car. There was also some evidence that Mr. Aitken wasn't moving at all when he was arrested, but had stored the guns in his car because his roommate was throwing a party, and he didn't want the guns in the apartment while guests were there drinking."

Evan Nappen, who is representing Aitken in his appeal, says the story about the party came from a faulty police report. In any case, Nappen notes, it was not Morley's job to decide whether Aitken was moving. "That's a question of fact, not law, and questions of fact are supposed to be determined by the jury," he says. "The judge is supposed to instruct the jury on the law, and in this case he refused to let them even hear it. But besides that, for him to say there was no evidence presented that Brian was moving just isn't true."

Without the exception, the jury's job was easy. In New Jersey, possession of a firearm without a permit is a felony, punishable by a mandatory minimum sentence of five years in prison and a maximum of 10. Aitken was convicted and sentenced to seven.

The prosecutors had some discretion here. They could have decided that Aitken plausibly thought he qualified for the moving exception, or that it wouldn't be in the interest of justice to charge him with a felony punishable by five to 10 years in prison. There is no evidence that Aitken threatened anyone with his guns or intended to use them for any nefarious purpose. Even the version of events least favorable to Aitken—that he put the guns in his trunk to keep them away from party guests who might have been drinking—shows him to be a responsible and conscientious gun owner. Morley acknowledges as much. "I can see the point that taking the guns away from the party might have been the responsible thing to do," he says. But he adds that still wouldn't entitle Aitken to the moving exception.

There's a happy ending: On December 20, Gov. Christie commuted Aitken's sentence. Aitken came home on December 23rd. His felony conviction still stands, but he will fight to clear his record through the appeals process.

It's good that Christie intervened, but it's a sad state of affairs that he had to. Putting Brian Aitken in prison wouldn't have made New Jersey any safer. It might, however, make some of the state's residents think twice before calling the police, particularly if they own guns. It might even make some New Jersey gun owners wonder if they have more to fear from the state's ridiculous laws and overly aggressive cops and prosecutors than they do from criminals. Given what happened to Aitken, those fears wouldn't be unfounded.

Radley Balko (rbalko@reason.com) is a senior editor at reason.