STONES and bones rarely make the front page, and even less frequently in the same month, but this has been no ordinary month. And it’s not over yet.

On May 4, The New York Times announced that the Metropolitan Museum of Art would voluntarily repatriate twin 10th century statues to Cambodia, after the museum received “dispositive” evidence that the pieces were products of the illicit antiquities trade.

A few miles away and a few days later, the U.S. Department of Homeland Security celebrated the not-so-voluntary repatriation of a looted 70-million-year-old Tyrannosaurus bataar (a relative of Tyrannosaurus rex) to Mongolia, having seized it from a self-described “commercial paleontologist” (and now confessed smuggler) named Eric Prokopi. Taken from the Gobi Desert, the dinosaur bones were seized last year after Prokopi tried to sell them in violation of U.S. and Mongolian law.

Meanwhile, on Wednesday, Cambodia publicly called upon other American museums to examine their Khmer collections and return any pieces that were plundered after the start of the country’s civil war in 1970.

With these two high-profile returns, attention may turn to Sotheby’s auction house next. The historic institution is fighting in New York courts to hawk a Cambodian sculpture that — along with the Met’s pair — once formed a three-dimensional tableau at the ancient temple of Koh Ker. These stone figures remained in situ for a millennium, until the country descended into war against the Khmer Rouge, when they were allegedly looted and trafficked overseas. Having traveled around the world through illicit and licit markets, the statues finally resurfaced in Manhattan.

In 2011, the Cambodian government asked Sotheby’s to return the piece in its possession, and enlisted the help of the U.S. government when the auction house declined. As a result, Sotheby’s now finds itself in the sights of the very federal agents and attorneys who so successfully investigated and prosecuted the T. bataar case.

Of course, Sotheby’s may still follow the Met’s lead, decide that its reputation is more important than a high-end sculpture, and repatriate the contested piece. But at the least, this month’s headlines offer a lesson. In both the Met and T. bataar cases, the looted items are going home. While the press and public are now honoring the museum, Prokopi is facing years in prison and hundreds of thousands of dollars in fines.

Of course, the return of treasures like these to Phnom Penh and Ulan Bator are still the exception, but they are growing as governments, law enforcement agencies and the public increasingly realize that looting cultural treasures is a crime — and not a victimless one. Just last year, the Dallas Museum of Art returned to Turkey a 194 A.D. mosaic, “Orpheus Taming Wild Animals,” which was likely looted from the floor of a Roman building in the southeastern part of the country.

But even as these returns are being made, looters are devastating ancient sites in search of prized artifacts to sell on the international market. To underscore the point, the very week that one of us visited the ancient Roman cities of Leptis Magna and Sabratha in Libya, we heard about the looting of a “heavyweight” statue in the middle of the night.

The smuggling of stolen cultural objects has become an underground industry that spans the globe. Though the F.B.I. estimates that the value of this black market is as much as $6 billion a year, we do not really know the actual extent of the trade in illicitly obtained antiquities. (Researchers at the University of Glasgow have received a $1.5 million grant from the European Research Council to attempt to quantify and qualify it.) Nevertheless, if looting on the current scale continues, by the time we have accurate numbers there will be much less of our world heritage to protect. This will not only be a loss for culture and science — there are additional if not readily apparent side effects. The black market in antiquities has been reported as a source of income for organized crime, rebel fighters and even terrorist groups.

The U.S. government, and specifically the Department of Justice and the Department of Homeland Security, should be commended for treating the illicit trade in cultural objects like the crime that it is, protecting the past, and improving America’s international relationships in the process.

The Metropolitan Museum of Art in New York should likewise be praised for refusing to hold on to looted antiquities. Unlike Prokopi, museum authorities did not wait for a court order or lawsuit to return stolen property, thereby demonstrating that it is never too early to do the right thing. In light of this month’s news, it is hoped that Sotheby’s and others will realize that it’s never too late, either. As Edmund Burke said, “All it takes for evil to triumph is for good men to do nothing.”

Mark V. Vlasic, a senior fellow and adjunct professor of law at Georgetown University, served as the first head of operations of the World Bank’s Stolen Asset Recovery Initiative and leads the international practice at Madison Law & Strategy Group. Tess Davis, a researcher at the University of Glasgow, served as the executive director of the Lawyers’ Committee for Cultural Heritage Preservation, and is working with Cambodia to combat the illicit trade in the kingdom’s antiquities.