The investigators from Florida could tell Samuel Little was excited when the photos came out. He started shifting in his chair. He looked them in the eye.

“The more you tell us, the more pictures we can show you,” Miami-Dade Police detective David Denmark remembers telling the 79-year-old man eager for each reminder: the sundress, the necklace, the faces of the women Little says he strangled decades ago and likes to call his “babies.” Crucially, Denmark says, Little only got to see what he could first describe on his own — bits of the story he’d already volunteered to another investigator.

The two cold cases Miami-Dade authorities pulled from a dusty warehouse made an uncanny fit with Little’s recollections, from the cement arch he said he drove under before choking Miriam Chapman to the way he buried Mary Brosley with her leg sticking out because the dirt was so hard.

“We knew what the deal was because he had given these details without even talking to us,” Denmark told The Washington Post.

It’s those kinds of details that have persuaded authorities to declare Little the most prolific serial killer in U.S. history, a title that takes more than confessions to earn. Little’s late-in-life disclosures to a Texas investigator were just the start of law enforcement’s efforts to confirm a record 50 killings by the same man — while avoiding the pitfalls that humiliated officials in the same state in the 1980s when another convict recanted hundreds of murder confessions.

That debacle, and a long history of police eager to close closes, has taught experts to approach confessions with great skepticism. Some met Little’s macabre milestone this week with questions: What had Little been told? Could he be spinning stories based on cues from his interrogators?

But investigators say their methods are very different from those of the authorities who once let a suspected serial killer see unsolved case files. They’re still working to corroborate dozens of Little’s 93 murder claims.

“Everyone’s kind of skeptical because unless you’re working with him … it’s hard to convey to somebody just how precise he is,” said Angela Williamson, a liaison between the Justice Department and the FBI who has listened to many of Little’s interviews.

“A lot of prolific killers have notes or trophies or things like that,” she said. “And for Little, it's all in his head.”

Troubling history

False confessions are widely documented. One database that aims to compile every U.S. criminal exoneration since 1989 found they were given by 27 percent of people convicted and then cleared of homicide.

But few false confessions have imploded as dramatically as Henry Lee Lucas’s.

Lucas shot to fame in 1983 after stunning a Texas courtroom — where he was on trial for an elderly woman’s murder — with the declaration that he had “100 more out there somewhere.” The Texas Rangers, a renowned group of state investigators, got to work extracting the dark history of a man convicted of killing his mother.

Lucas would confess to some 600 murders as law enforcement from around the country queued up to grill him on thousands of their unsolved cases. Newspapers and TV stations described a one-eyed “drifter” and fifth grade dropout who recounted his crimes with little visible emotion — like a man “reciting his grocery list,” as reporters for The Washington Post put it.

More than 200 cases were cleared in Lucas’s name as law enforcement touted corroborating facts and telling details.

Then, a reporter started digging.

Hugh Aynesworth met Lucas in his Texas jail cell in the fall of 1983. Lucas had admitted to killing more than 150 women at that point, Aynesworth recounted, but he told the veteran journalist he’d really murdered just three.

“They're goin' wild every time I tell 'em about some more,” Aynesworth said Lucas confided. “I'm gonna show 'em. They think I'm stupid, but before all this is over, everyone will know who's really stupid. And we'll see who the real criminals are."

Tracing Lucas’s travels over the years through food stamp applications, paychecks and other records, Aynesworth realized the timeline of his purported crimes didn’t add up. He and another journalist concluded in a front-page article for the Dallas Times-Herald that Lucas’s confessions amounted to “the largest hoax in law enforcement annals."

The revelations shocked just like Lucas’s courtroom declaration less than two years earlier. They also pained the people who had gotten closure for loved ones’ deaths.

″They don’t know what this is dragging us through,″ one man told the Associated Press amid new doubt about his wife’s murder. ″It’s like it just happened yesterday.″

The Rangers defended their work, but Texas’s attorney general weighed in after a year-long investigation to say police ignored red flags in their eagerness to clear their books. Absent any physical evidence linking Lucas to his alleged crimes, the attorney general said, law enforcement fed the convict the case details that he wove into elaborate stories — encouraged by milkshakes, steaks, TV privileges and promises of no death penalty, according to various newspaper accounts. A Texas Monthly article notes one memo from the Rangers describing how Lucas got pictures and victim information to “refresh” his memory.

Law enforcement’s practices have improved since the Lucas case, said Richard Leo, an expert on police interrogation and false confessions. The University of San Francisco professor of law and psychology told The Post a nationwide shift toward recording police interviews has provided new accountability for actions that could “contaminate” a confession.

But case after case of police work gone wrong has made him distrustful, and he still hears of officers who taint confessions by trying to confront suspects with bits of a case. He’s seen DNA evidence exonerate people whose confessions were proclaimed too detailed to be made-up — and wished for interview recordings that could clear up where the convict got their facts.

“Interrogators feed details to people they interrogate without realizing it,” he said.

Alan Hirsch, who also studies false confessions, holds similar doubts. The chair of the Justice and Law Studies Program at Williams College says members of law enforcement are still too quick to believe confessions and prosecutors too willing to “cherry-pick” from them while discounting errors.

He and Leo also worry about the incentives for tall tales that authorities gave Henry Lee Lucas. Promises that suspects won’t get the death penalty if they talk risk drawing out a false story, they said, and can get a confession suppressed in court.

The small perks can matter, too. Hirsch says he’s currently consulting for the defense in a case where an alleged serial killer facing capital punishment gave more than a dozen false, “ever-changing” confessions. The suspect’s apparent motive, Hirsch said, was straightforward: He asked for coffee and cigarettes whenever he visited the interviewing room.

Little, like Lucas, was assured he would not face the death penalty if he spilled what he knew, his lead interviewer — a Texas Ranger — has said. As with Lucas, Little’s stories were coaxed out over food and milkshakes, along with friendly chitchat and ego-stroking to build up the rapport that cracked the killer’s long silence.

The Texas Rangers did not respond to inquiries, but Mary Kay Tylee, a public defender who represented Little as he pleaded guilty to murder in Ohio this summer, confirmed that her client only talks to local law enforcement after getting a letter promising no capital punishment.

From everything Tylee’s seen of the taped questionings, Little has led the conversation, the defense attorney said. She says Little is “making the amends he can” with his confessions, though she could not say whether he feels any remorse.

“The stuff was really coming from him,” she said.

Devastating details

Little didn’t talk at first.

Arrested in 2012 for a drug offense, he pleaded his innocence after investigators matched him to DNA found on three women strangled in Los Angeles in the 1980s. “I didn’t do it!” he screamed out in front of the victims’ family members before being sentenced, according to the Los Angeles Times. He received three lifetimes in prison without the chance of parole.

Christie Palazzolo, an analyst at the FBI’s Violent Criminal Apprehension Program (ViCAP), was searching a national crime database for other potential Little murders, comparing the killer’s whereabouts over the years with unsolved cases. She struck on a 1994 strangling in Odessa, Tex. that “just felt like him,” as she would later tell a reporter. But the pieces didn’t come together until last year, when Palazzolo joined forces with Williamson from the Justice Department and Texas Ranger James Holland, who’s made a specialty of extracting confessions. The three traveled to California that May to see what Little would tell them.

Little had been unwavering in his innocence, Palazzolo said. But then, after some banter, Holland asked if he had ever been to Odessa, and a torrent of details poured out: the victim’s looks, the time he spent with her boyfriend, the place he left the body. Almost everything fit the case file.

Then came the new stories — cases the team had never heard of but would confirm on nuances they found equally convincing, Palazzolo and Williamson recounted. Once, Little detailed a victim’s last meal, they said. His account matched the contents of the woman’s stomach noted down from an autopsy.

Little had a good recall for place, Palazzolo says, and with each new story, they contacted local agencies to see what they had on record. But the confessed killer was far shakier on dates — his memory of the Odessa killing was off by a decade — which typically meant combing through 20 years of files. And Little’s penchant for strangling rather than shooting or stabbing meant that many of the deaths he confessed to were harder to detect as homicides. Some were recorded as drug overdoses.

Sometimes, local officers would probe Little about other cases they’d unearthed that seemed to fit his path and methods — a practice that, when done clumsily, can raise experts’ concerns about false confessions.

But unlike Henry Lee Lucas, investigators said, Little would just say, “I didn’t do it.” That frankness helped convince Darrell Prewitt, a sheriff’s lieutenant from Arkansas, who had flagged several cases but closed just the one that he says Little rattled off unprompted.

The victim in that now-solved case, pulled badly decomposed from a river, has yet to be identified. Little’s startling recall could help with that, too, Prewitt said. The convict drew a picture.

Investigators started asking Little for victim portraits after discovering that his prison cell walls were covered in drawings of celebrities, Palazzolo and Williamson said. They learned he once painted a mural. Now, his portraits are posted online in the hopes they might jog new leads.

For Miami-Dade Detective Denmark, Little’s artistry also offered one last tiny, damning detail rooted in meticulous police work from 1976. A nightclub owner interviewed at the time recalled seeing Miriam Chapman in the company of a man who said he’d like to paint a mural on the establishment’s wall.

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