In 2015, millions of people watched Making a Murderer, a Netflix documentary series about the murder prosecutions of two Wisconsin men. Opinions varied on the guilt of the program’s central figure, Steven Avery, who was convicted of killing Teresa Halbach, a 25-year-old photographer.

But many people were made powerfully uneasy by the treatment of Avery’s nephew, Brendan Dassey, whose videotaped interrogation was among the most gripping parts of the series.

Dassey, 16 at the time, was a study in pathos: hapless, lost, scared, painfully awkward, trusting, susceptible to suggestion and close to if not over the borderline of intellectual disability.

Two investigators feigning fatherly concern fed Dassey crucial details and elicited a halting, mumbled and contradictory confession. On the strength of that confession and almost nothing else, Dassey was convicted and sentenced to life in prison for raping and murdering Halbach.

On Thursday, the Supreme Court will consider whether to hear Dassey’s appeal.

The court has long said that “the greatest care must be taken” in making sure confessions obtained from juveniles are voluntary. Dassey’s case could allow the justices to assess whether that command was taken seriously by courts in Wisconsin, which refused to suppress his confession.

It could also allow the justices to consider mounting evidence that false confessions from juveniles play a role in a disproportionate share of wrongful convictions. According to one study, 42 percent of exonerated juveniles had falsely confessed, compared with 8 percent of adults.

Dassey was interviewed for hours without a lawyer, a parent or any other adult who might have been alert to his interests. But the investigators who questioned him assured him that he had nothing to fear from them

Timeline: Steven Avery's convictions Show all 5 1 /5 Timeline: Steven Avery's convictions Timeline: Steven Avery's convictions 1985: Steven Avery is falsely convicted of raping a Penny Beernsten She was jogging along the shore of Lake Michigan when she was threatened with a knife and attacked. Ms Beernsten identified Avery as her rapist from a line-up that did not include the actual attacker. AFP/Getty Images Timeline: Steven Avery's convictions 2003: Conviction overturned Avery's 32-year prison sentence was overturned after DNA testing by the Wisconsin Innocence Project proved his innocence and found a hair from Gregory Allen. He was convicted of the rape and Avery was released. Timeline: Steven Avery's convictions 2004: Avery files federal lawsuit against Manitowoc County police A Wisconsin Department of Justice investigation found police had committed no criminal offences or ethics violations, sparking a lawsuit from Avery seeking $36 million compensation. Timeline: Steven Avery's convictions 2005: Avery is arrested for Teresa Halbach's murder His Avery Auto Salvage business was the freelance photographer's last appointment of 31 October. She was reported missing four days later and police later found her car, bones, teeth and belongings at the site. Avery pleaded not guilty but was sentenced to life in prison in 2007. Timeline: Steven Avery's convictions 201: Netflix releases Making a Murderer The 10-episode documentary came after Avery's conviction was upheld in a 2011 appeal.

“Yeah, we’re cops, we’re investigators and stuff like that, but not right now,” said Tom Fassbender, a special agent with the Wisconsin Department of Justice. “I’m a father that has a kid your age, too. I want to be here for you. There’s nothing I’d like more than to come over and give you a hug.”

The investigators teased out contradictory statements from Dassey, steering him towards their theory of the case.

They knew, for instance, that Halbach had been shot in the head, though this fact had not yet been made public. What followed was like a game of 20 Questions.

“Something else was done,” said Mark Wiegert, an investigator with the Calumet County Sheriff’s Office. “Something with the head.”

Dassey’s first try: Avery had cut off Halbach’s hair.

His second try: Avery had punched her in the head.

His third try: Avery had told him to cut Halbach’s throat.

At this point, Dassey gave up. “That’s all I can remember,” he said.

But the investigators were not done. “All right,” Wiegert said. “I’m just going to come out and ask you. Who shot her in the head?”

Thus prompted, Dassey said that “he did,” referring to his uncle.

Asked why he had not mentioned that shocking assertion earlier, Dassey said, “Because I couldn’t think of it.”

By the end of the interrogation, Dassey had confessed to gruesome crimes. Then he asked if he could return to school in time for a sixth-period class. He had a project due.

When his mother asked him how he had been able to answer the investigators’ questions, he said he had guessed. “That’s what I do with my homework,” he added.

Dassey and his family were completely overmatched by the criminal justice system. In a call to his mother from jail, for instance, Dassey said he had been told that some of his statements had been “inconsistent.” He did not know what the word meant, so he asked his mother. She did not know, either.

A Wisconsin appeals court upheld Dassey’s conviction. But a federal judge and a divided three-judge panel of the 7th U.S. Circuit Court of Appeals, in Chicago, ruled that Dassey’s confession should have been suppressed. Without the confession, Judge Ilana Rovner wrote for the majority, the case against Dassey basically evaporated, as “no one ever found a single hair, a drop of blood, a trace of DNA or a scintilla of physical evidence linking Dassey to this crime.”

The full 7th Circuit reversed the trial judge’s decision by a 4-3 vote, saying that Dassey could not overcome barriers in a 1996 federal law that makes it hard for federal courts to grant relief to people convicted in state courts.

In dissent, Chief Judge Diane P. Wood wrote that this was a “travesty of justice.”

Dassey is represented by Seth P. Waxman, who served as U.S. solicitor general in the Clinton administration and later helped persuade the Supreme Court to abolish the death penalty for juvenile offenders.

“Put simply,” Waxman wrote in his petition seeking review in the new case, Dassey v. Dittmann, No. 17-1172, “the interrogators took advantage of Dassey’s youth and mental limitations to convince him they were on his side, ignored his manifest inability to correctly answer many of their questions about the crimes, fed him facts so he could say what they wanted to hear, and promised that he would be set free if he did so. The resulting confession was more theirs than his.”

The Supreme Court seldom agrees to hear cases merely to correct errors in a single case, even ones with grave consequences. But a supporting brief filed by scores of current and former prosecutors urged the justices to hear Dassey’s appeal in light of the attention Making a Murderer had drawn to his confession.

“It affected the way everyday Americans view our justice system,” the prosecutors wrote.