Sue Aitken called the police because she was worried about her son, Brian. She now lives with the guilt of knowing that her phone call is the reason Brian spent his 27th birthday in a New Jersey prison last month. If the state gets its way, he will be there for the next seven years.

Aitken was sentenced in August after he was convicted of felony possession of a handgun. Before his arrest, Aitken, an entrepreneur and owner of a media consulting business, had no criminal record, and it appears he made a good-faith effort to comply with New Jersey's stringent gun laws. Even the jurors who convicted him seem to have been looking for a reason to acquit him. But the judge gave them little choice. Aitken's best hope now is executive clemency. He is petitioning New Jersey Gov. Chris Christie for a reprieve this week.

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

In December 2008 Aitken made a final trip back to Colorado to collect the last of his possessions, including the three handguns he had legally purchased in Colorado—transactions that required him to pass a federal background check. Aitken and his friend Michael Torries had found an apartment in Hoboken, and Torries accompanied Aitken to Colorado to help with the last leg of the move. According to testimony Torries later gave at Aitken's trial, 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 the 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 been refusing to let him see his son. When Aitken visited his parents' house, his mother, Sue Aitken, grew worried about his mental state. In an interview with a New Jersey radio program last week, she said she works with children who have mental health problems, and she has always been taught to call police as a precaution when someone appears despondent and shows any sign that he might harm himself. Concerned about her son, she called 911 but then thought better of it and hung up the phone. The police responded anyway. When they arrived at her home, Sue Aitken told them her concerns about her son, and the police called Brian Aitken, who was then en route to 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. They were 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.

To buy a gun in New Jersey, you must go through a laborious process to obtain a "purchaser's permit." But that permit doesn't entitle 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 against the charge of illegal gun possession by claiming one of the state's exemptions.

Evan Nappen, who is representing Aitken in his appeal, likens the process to claiming self-defense in a murder case. "If you kill someone because they're about to kill you first," he says, "you're still guilty of homicide. You have to prove you should be granted the exception for self-defense. It's the same thing for just about all New Jersey gun owners. You're guilty until you prove that you're 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. Brian Aitken claimed he was moving between residences, and there is pretty strong evidence that he was. Sue Aitken testified that her son was moving his belongings from her house to his. So did Aitken's roommate. One of the police officers at the scene testified that Aitken's car was filled with personal belongings.

Yet Judge Morley wouldn't allow Aitken to claim the exemption for transporting guns between residences. He wouldn't even let the jury know about it. During deliberations, the jurors asked three times about exceptions to the law, which suggests they weren't comfortable convicting Aitken. Morley refused to answer them all three times. Gilbert and Nappen, Aitken's lawyers, say he also should have been protected by a federal law that forbids states from prosecuting gun owners who are transporting guns between residences. Morley would not let Aitken cite that provision either.

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 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. 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." Echoing the prosecutor's office, Morley says: "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."

Gilbert and Nappen say the story about the party came not from Aitken, his parents, or his roommate but from a faulty police report. In any case, Nappen adds, 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.

"New Jersey gun laws are insane," Nappen says. "It makes a criminal of every gun owner and forces him to prove his innocence." Worse, in 2008 the New Jersey legislature and then-Gov. John Corzine changed the law to make the penalty for possessing a gun the same as the penalty for using it to commit a separate crime. That means someone like Aitken gets the same punishment as someone who assaults another person with a gun. In November 2008, New Jersey Attorney General Anne Milgram issued a directive (PDF) urging the state's prosecutors to apply the new law "vigorously," "strictly," and "uniformly."

Even with Milgram's directive and the state's draconian gun laws, prosecutors have some discretion. They could have decided that Aitken plausibly thought he qualified for the moving exception or that, even without the exception, 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. Even 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 acting responsibly did not entitle Aitken to the moving exception.

Putting Brian Aitken in prison isn't going to make 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 is a senior editor at Reason magazine.