Former Jasper Johns assistant James Meyer, 52, has pleaded guilty to stealing the artist’s paintings from Johns’s Connecticut studio and selling them for a $3.4 million profit, reports Bloomberg News.

Meyer, who worked for Johns for more than 25 years, had been charged with a single count of transporting stolen property for stealing 22 of the artist’s works between September 2006 and February 2012. He sold the works to an unidentified gallery, claiming Johns had given him the canvases as gifts. The gallery went on to sell the paintings, which were actually unfinished pieces Johns had not authorized for sale, for $6.5 million.

In order to cover his tracks, Meyer gave each work a fake inventory number, and doctored up ledger pages from the artist’s studio, giving photos of the falsified documents to the gallery as evidence that the paintings came from the artist’s studio and had been gifted to Meyer. Those photos were then emailed to prospective buyers by the gallery. As a condition of the sales, Meyer required the artworks not to be publicly exhibited or resold for at least eight years.

“James Meyer made millions by stealing and selling the valuable artworks that he was entrusted with maintaining,” said Preet Bharara, a Manhattan attorney, in a statement. “With his guilty plea today, Meyer will now have to pay for that decision.”

The case appeared in Manhattan federal court before US District Judge Paul J. Oetken, and Meyer could have faced up to 10 years in jail. He has accepted a plea deal, and has agreed to non-binding federal sentencing guidelines that call for up to three years and 10 months in prison. Currently, Meyer is free on bail as he awaits his December 10 sentencing date. He has also agreed to forfeit more than $3.9 million, according to Courthouse News.

Another fraud case involving Johns and the operator of a foundry where he had sculptures made, Brian Ramnarine, also ended with a guilty plea. Ramnarine will be sentenced in September, according to the Guardian.