As J. Ross Baughman, a Pulitzer Prize-winning photojournalist, prepared to downsize into a new apartment in 2020, he realized he would not have the wall space for his entire collection, which included prints by marquee names like Diane Arbus and Richard Avedon.

Hoping to sell about a third of it, he reached out to Thomas Halsted, a Detroit-area gallery owner who in the early 1970s had helped Baughman acquire his first artwork, an Arbus print of a human pincushion.

Halsted’s daughter, Wendy Halsted Beard, broke the news that he had died. But she had inherited the business, and within a month, Baughman agreed to consign the Arbus and 19 other prints, many of them signed by the photographers.

Their contract gave Beard one year to sell the photos, which she valued at $40,000. But nearly three years later, Baughman has not received a cent — or any of his cherished images back.

Baughman, 69, is one of several victims in what the F.B.I. has called a criminal scheme by Beard to swindle older collectors, including an 89-year-old man with Alzheimer’s disease, out of $1.6 million worth of fine art photos.

Beard allegedly went to great lengths to deceive her clients, according to court documents, creating email addresses for nonexistent employees, making up a double lung transplant and other medical emergencies, and swapping one client’s signed photograph with a $405.26 purchase from the Ansel Adams Gallery’s gift shop.

Baughman said he grew suspicious when Beard became evasive about the status of his prints. Then emails to her started to bounce back.

“She was willing to take advantage of me,” said Baughman, who had received some of the images he had consigned as gifts from his photography students. He said it felt like “she had taken my life’s work — all of these very fun, sentimental personal artifacts.”

Beard, who is in her late 50s, has been charged with wire fraud and bank fraud. Her lawyer, Steve Fishman, said that “this is a complicated case which does not lend itself to any commentary right now.”

In a criminal complaint filed in the U.S. District Court for the Eastern District of Michigan last year, the F.B.I. alleges that Beard repeatedly obtained fine art photographs on consignment with the intent of defrauding collectors.

When the images did sell, including a $440,000 transaction for a large Adams print from Grand Teton National Park, Beard kept all the profits rather than just her commission, the complaint said. When they failed to sell, she did not return the photographs as promised, instead keeping them in her Franklin, Mich., home or abandoning them in a Florida gallery.

In another unresolved deal, the F.B.I. said a 72-year-old longtime friend of Beard’s paid her $73,000 for a copy of “Moonrise, Hernandez, New Mexico,” one of Adams’s most famous photographs, but never received the work. Referring to one of the medical emergencies the agency determined were fictitious, Beard explained the delay in an email to her friend:

“On Computer finally. Been a crazy last bit….Not all gone but at least out of the months long coma. Nice to see the sunshine sorry so short more later.”

The F.B.I.’s criminal complaint detailed the experiences of five victims, including Baughman, who was in his 20s when he received the 1978 Pulitzer Prize in feature photography for his war reporting in Zimbabwe, then called Rhodesia. Bank records and business records, the complaint said, indicated that there were likely to be more victims.

One person who was not part of the complaint had an unsettling realization about his two Adams photos after watching a television reporter detail the accusations against Beard, said Fritz Knaak, a lawyer based in St. Paul, Minn., who represents the anonymous victim.

Knaak said his client was a serious collector who knew Beard personally and consigned the two photos, valued at $30,000, with her in late 2019.

“It’s very embarrassing to have to admit to your peers that maybe you’ve been taken advantage of,” Knaak said. “What made it most painful was a violation of trust in a fairly small circle of collectors.”

The most valuable photograph that the F.B.I. said was stolen was a mural-size print by Adams titled “The Tetons and the Snake River, Grand Teton National Park.” Beard sold it for $440,000 to a gallery in Jackson Hole, Wyo., near where Adams took the black-and-white landscape of a river winding toward snow-capped mountains.

But the agency alleges Beard never bothered to tell the print’s original owner, an 82-year-old who had consigned $900,000 worth of fine art photography with her. Beard was due a 5 percent commission for her efforts, but the F.B.I. said she took the full amount of the Adams sale instead.

The print was sold several times after that, eventually landing in a private home in Idaho for a price of $685,000. It is unclear if that work or any of the other photos, many stowed away as F.B.I. evidence, will be returned to their original owners.

Baughman met Halsted, Beard’s father, in 1972 at his gallery in the ritzy Detroit suburb of Birmingham. Baughman was a budding photographer, while Halsted was an entrepreneur and early believer in the field of photography as fine art.

They became friends after Halsted sold Baughman a print of a little-known photo by Arbus titled “The Human Pincushion, Louis Ciervo, in His Silk Shirt, Hagerstown, Md., 1961,” an arresting portrait of a man working as an oddity attraction at a circus. Baughman had recently seen her work at a landmark photography exhibit at the Metropolitan Museum of Art in New York.

“The fact that it was more than $250 seemed pretty stiff to me back in college days,” Baughman said of the print.

Decades later, Beard valued “Human Pincushion” at $8,500. As their consignment agreement ended, Baughman asked Beard whether there “was even a tiny nibble of interest” in his prints and said he would be happy to renew their contract under the same terms.

In her response two weeks later, Beard wrote of health issues and asked if she could lower the asking prices.

“Sorry for the delay. Hope you are well,” Beard wrote. “We have just survived a bout of covid where all 4 of us got at same time so a bit behind on life.”

After he agreed to lower the price, Baughman says he never heard from Beard again.

In an attempt to track her down, Baughman contacted a gallery in Palm Beach, Fla., where Beard said she was displaying his photos. He was told to contact “Katy Welsh,” an alias that Beard had used with other clients, according to the F.B.I. (A representative from the gallery, Palm Beach Art, Antique & Design Showroom, said the photos Beard left were no longer there but declined to comment further.)

Baughman is still trying to recover his prints, which he now considers even more precious.

During the consignment saga, an apartment fire destroyed his collection of cameras and photo books, and nearly one million negatives and transparencies were turned to ash. “I finally have enough space on the wall where I can hang these pictures,” he said.