While many American cities have seen a significant increase in the number of guns stolen from often unlocked cars, Tennessee seems to be the leader in this area. In 2016 2,203 guns were reported stolen from vehicles. In 2017 4,064 thefts were reported. The causes of the increase are no mystery. One factor is the law. Tennessee passed a law that allowed people to keep guns in their vehicles without a permit or any training. As would be suspected, this helped increase the number of people keeping guns in their vehicles. A second factor is fear: people worry about violence and anecdotes of car jackings abound. Hence people are more likely to carry a gun in their vehicle. A third factor is that when more people have guns, more people want to have guns because they are worried about the other people who have guns. This motivates both the carrying and theft of guns.

Because some of the stolen guns are being used in crimes, there has been a proposal in Tennessee to make it a crime to fail to secure a gun stored in a vehicle. As would be expected, this proposal has met with strong opposition. One argument against the proposal is based on the claim that it would make criminals out of law-abiding citizens. One obvious reply is that this is true of any new law that makes something a crime. What was legal is now a crime, thus citizens who were law-abiding would be criminals if they did not obey the new law. But, as with any law, there is the question of whether it would be a good law.
It could also be argued that the gun owner is, obviously, the victim when their gun is stolen, and they should not be punished for failing to protect their property from theft. To use an analogy, surely no one would ever blame the victim of a sexual assault for being assaulted and to suggest that the victim should have been more cautious would be wrong. Likewise, for people who leave guns unsecured in cars. A such, the law should focus on punishing the thief rather than the victim.
While the analogy has considerable appeal, perhaps there is a better analogy here. In my adopted state of Florida pools must be properly fenced and pool gates must close automatically. This is because pools present a hazard and those responsible for them have an obligation to not endanger the public through their negligence. If a child wanders into my pool and drowns because I did not secure it, that death is partially my responsibility—I am not morally protected by property rights to do as I wish with my property.
The same reasoning could be applied to guns: an unsecured gun presents a potential danger to the public and the owner is obligated to take at least minimal effort to secure it. This obligation does not extend to property in general: if someone steals your iPad from your car, that is your loss and does not put others at risk. If someone steals your .45 from your unlocked car, you do suffer a loss, but the public is now at risk from an armed criminal.
One could raise the obvious counter: securing a pool is to protect children who do not know any better, while securing a car is to keep out people who know exactly what they are doing. So, while securing your vehicle is a good idea, the obligation is not on you to secure it, but on other people to not steal from your vehicle.
I must admit to being morally split here. On the one hand, I do agree that in general people are under no moral obligation to secure their property and that other people are obligated to not steal from them. Roughly put, stealing is wrong; not securing your property is just stupid. As such, the law should generally aim at punishing theft rather than failure to secure.
On the other hand, people do seem to be morally responsible for dangerous property and obligated to take reasonable steps to secure it. This seems especially important in the case of guns since they can be used to harm others. The concern here is that it is not the intruder who is at risk, rather it is other people who could be harmed by the thief using the stolen weapon—which would not have been readily available if it had been secured. As such, this could be seen as relevantly similar to the pool analogy: the concern is about the innocent people who might be harmed by the negligence of the owner. As always, the mere fact that something is morally wrong does not automatically entail is should be illegal—so the legal question remains.
One stock counter to imposing legal responsibilities on gun owners is, of course, an appeal to the Second Amendment. The idea is that such restrictions are unconstitutional since they limit the right to keep and bear arms. One stock reply is to point out all the legal restrictions that have passed muster—although these can obviously be debated as well. Another option is to point out that there are principled restrictions on other fundamental constitutional rights. To use a popular example, the 1st amendment does not allow dangerously irresponsible speech, such as falsely saying that you have a bomb while on a plane. The same should hold true for the 2nd—it is not carte blanche for irresponsible behavior and hence it would be acceptable to impose certain laws requiring such behavior as a condition of exercising the right. The question then becomes whether such a law would be unduly burdensome or unreasonable.
On the face of it, requiring people to secure their guns properly in their vehicles is neither burdensome nor unreasonable. After all, locking the doors is quick and costs nothing. While, as noted above, some have proposed making failure to secure a gun a crime, it seems more reasonable to impose a sensible and effective penalty: the violator would be required to acquire a means of properly securing the gun (such as a gun lock or gun safe). While there might be concerns about cost, these devices are cheaper than the gun they are supposed to secure and hence should be affordable. Pro-gun groups could also use some of their resources to offer discounts to poorer gun owners so they can purchase the basic means to secure their guns.
Securing one’s gun is a basic responsibility of gun ownership and those who want to exercise this right are obligated to fulfil this responsibility. As such, requiring people to properly secure their guns is reasonable and just, provided that the law does not impose any burdensome requirements or unreasonable punishments.