Using the BLM’s computerized records maintained in Denver and obtained through the Freedom of Information Act, the AP found that 32,774 of all adopted animals–or 20%–remain untitled. Legally, those horses and burros are still federal property.

The adopted horses were given to more than 18,000 different people.

Last month, the AP reported that the $16-million-a-year program has allowed thousands of titled wild horses and burros to be slaughtered. The investigation found that BLM employees are among those profiting from the slaughter.

In response to the first report, Wild Horse and Burro Program chief Thomas Pogacnik wrote: “Once title is issued, the animal is private property.”

Under the 1971 law, Interior Secretary Bruce Babbitt is mandated by Congress to protect wild horses and burros on public lands. Babbitt refused to comment for this story.

BLM officials say they rely on spot checks to trace horses that remain untitled. But Larry Woodard, the former state director of New Mexico’s BLM office, called spot checks inadequate.

“One out of every five animals adopted by the bureau never being titled would indicate that the titling aspect of the adoption program has not been a subject of intense concern,” Woodard wrote in a 1993 memo.

A U.S. Justice Department memo from April 1996 indicated that the BLM is not carefully screening adopters because the agency does not want to know what happens to the animals.

“The Adopt-a-Horse program is seriously flawed. . . . BLM has an unstated policy of not looking too closely at proposed adoptions,” wrote Charles Brooks, a Justice Department attorney who had been assisting the U.S. attorney’s office in Texas with an investigation of the program. “The agency’s approach to this was its version of ‘Don’t ask, don’t tell.’ ”

A March 27, 1995, internal memo from that investigation quotes BLM law enforcement agent John Brenna as saying that Lili Thomas, a BLM official, made “a tacit admission of backdating documents used in the Wild Horse and Burro Program.”

Thomas did not immediately respond to messages requesting comment. Brenna refused to comment.

In the 25 years since the law’s passage, the BLM has gathered 165,635 animals in 10 Western states deemed “excess” and given most of them to adopters for $125 each. About 40,000 horses and burros remain in the wild.

Thomas Sharp, a 43-year-old wheat and alfalfa farmer, sits in a West Texas penitentiary, the only person in the country in federal prison for selling untitled horses.

He says he couldn’t afford to feed the animals and didn’t bother to send in a form requesting title. “They got me on a signature, but they got me, that’s for sure,” he said.

Assistant U.S. Atty. Hank Hockeimer of Oklahoma said he hoped Sharp’s four-month sentence would set an example.

“Our purpose for prosecuting this case was to send a message that under this program you can’t ostensibly adopt these horses and then sell them before you have title,” he said.

The AP contacted 20 adopters of untitled horses last week, but only two still had their animals. One said his horse died, another gave his away and the rest said they had sold their untitled horses, mostly at livestock auctions.

Wild horses sold at auction almost all eventually end up slaughtered, according to the operators of North American horse slaughterhouses.

George Varner Sr., who spent 20 years as a “killer buyer” for slaughterhouses, said one or two wild mustangs show up at auction barns each month in central Mississippi alone.

He said the only people willing to bid on the horses are the slaughterhouse buyers. “These horses aren’t good for anything else,” he said.

The AP’s Fred Bayles, Chris Sullivan and Drew Sullivan contributed to this report.