Aurora, Sandy Hook, San Bernardino, Orlando. The list is mind-boggling. Different locations, different shooters, different victims. But they share a common feature - a very specific type of gun, a semiautomatic rifle - a lethal weapon that can quickly unleash 75 to 100 rounds of ammunition.

Talk about efficiency. These are efficient killing machines. It doesn’t take much time to buy them. No need to pass a test of skill or knowledge. No special license required. No need to register. Just go to the store, pass a simple background check, plop down your money and then ready, aim, fire.

It’s American efficiency at its worse. These efficient killing machines - the weapons of choice for mass shooters, terrorists and for criminals targeting law enforcement officers - are available off the shelf in a matter of minutes.

EditorialEditorial: Higher costs could cut gun bloodshedDon't miss outSign up for The PointCartoonDavies' latest cartoon: At the employment office

It makes no sense.

But it hasn’t always been this way.

For 10 years, from 1994 through 2004, the United States banned the sale, manufacture or possession of semiautomatic assault weapons. Although there is evidence that, during the ban, use of these weapons and high-capacity magazines in crime decreased, there were also loopholes that enabled manufacturers to make certain modifications and continue producing this type of weapon. When the ban expired in 2004, Congress, concerned more for its members’ political lives than the lives of the American people, didn’t try to improve the law. It simply let it die.

advertisement | advertise on newsday

Although it is difficult to know how many assault-style rifles are in circulation today, the available data suggest that production and sales soared after 2004 - much to the delight of gun manufacturers, which profit handsomely from these weapons. Indeed, in 2013, the National Shooting Sports Foundation testified in Congress that there were probably about 5 million to 8.2 million such weapons in the United States. Many are in the hands of or easily accessible by those who should not have firearms, even people who the FBI suspects may be terrorists, people who can’t get on an airplane but can buy an efficient killing machine.

While Congress dithers, some of our schools, movie theaters, bars and workplaces have become shooting galleries.

Why do we continue to allow these guns to be sold to civilians?

Sign up for The Point

Go inside New York politics.

They are not used for self-defense. You certainly can’t tuck them in your trousers or pocketbook.

It hardly seems sporting to allow them to be used in hunting with so many more appropriate types of arms to use.

And there is no constitutional right to own them.

Supreme Court Justice Antonin Scalia, writing for the majority in the 2008 Heller decision, made that clear. The Second Amendment, he wrote, “is not unlimited. . (Nothing) in our opinion should be taken to cast doubt on long-standing prohibitions on the possession of firearms. . (We) also recognize another important limitation on the right to keep and carry arms. . The sorts of weapons protected were those ’in common use at the time.’”

But the NRA and its posse on Capitol Hill never like to talk about that part of the court’s ruling. Why talk common sense when it’s about dollars and cents?

advertisement | advertise on newsday

Some states have seen fit to ban this type of weapon in the face of federal inaction. But guns, like people, cross state lines very easily. So we need a federal solution, a new ban or at least stronger effective regulation of the sale and possession of assault weapons and high-capacity magazines.

Let us learn from the lessons of 1994-2004, and the years since. Let’s enact a law that deals not so much with what weapons look like as what they can do. Granted, we will need creative solutions to deal with the millions of semiautomatic rifles in circulation. But that’s why we send our representatives and senators to Washington - to come up with creative, workable solutions.

The longer we allow these weapons to be on the market, the easier we make it for hate-filled, rage-filled, troubled individuals to buy these efficient killing machines. There will be more funerals to attend, more moments of silence to observe and less security in our homeland.

Let’s be clear, though. A ban on assault weapons and high-capacity magazines is not a cure-all to eradicate all violence or stop all shootings, but it will make it much harder for the next killer to take down so many victims in such a short time.

Tell your lawmakers to act now before we have to add another city to that list of places in mourning because of these efficient killing machines.

advertisement | advertise on newsday

Shira Goodman ( shira.goodman@ceasefirepa.org ) is executive director of CeasefirePA ( www.ceasefirepa.org ), an anti-gun violence organization. Phil Goldsmith ( pgold4110@gmail.com