The arrest of Ternus and his co-conspirators depended on the cooperation of the Department of Justice, the U.S. attorney's office for the southern district of Florida, the FBI, ICE , and the French and Spanish national police.
In a statement e-mailed to ABC News, Acting Assistant Attorney General Matthew Friederich stressed the importance of interagency cooperation in a growing globalized and tech-savvy international crime network.
"Cooperation with our international law enforcement partners is crucial to fighting international organized crime," Friederich said. "Advances in technology and globalization, among other factors, mean these criminals can operate from almost anywhere in the world and still commit crimes in the United States. The cooperation in the case ... led directly to finding, arresting, and indicting this defendant, not to mention recovering these irreplaceable art treasures."
The investigation was part of a new international crime-fighting strategy that aims to build consensus and unity among different law enforcement agencies to "identify the most significant priority targets, and then significantly disrupt and dismantle those targets," according to a Justice Department release.
Ternus will likely be deported to France, according to Justice Department officials. No promises have been made, but officials added that Ternus is eligible for a sentence reduction if he cooperates with authorities in the investigation.
ABC News' Jason Ryan contributed to this report.