Washington (CNN) The Supreme Court declined on Monday to take up a case concerning Brendan Dassey, a central figure in a 2015 documentary television series "Making a Murderer."
Dassey was 16 when he was interrogated and confessed in 2005, and he was convicted in 2007. A federal appeals court ruled last year that his confession should not be thrown out.
Lawyers for Dassey argued he was sentenced to life in prison after being convicted of rape, murder and mutilation based solely on his confession with no physical evidence. They say the confession of the then-16-year-old was involuntarily coerced and that there existed no physical evidence linking him to the crime. After losing in the lower courts, lawyers for Dassey appealed to the Supreme Court.
The lawyers argued their client was subject to coercive police tactics and that he is borderline intellectually disabled. In court papers, they accused interrogators of feeding him the "right" answers.
A panel of judges on the 7th US Circuit Court of Appeals ruled against Dassey, holding that he spoke "freely" after Miranda warnings with his mother's consent.
In dissent, however, three judges said that Dassey was "subjected to myriad psychologically coercive techniques but the state court did not review his interrogation with the special care required by Supreme Court precedent."
Dassey's attorney, Laura Nirider, issued a statement on Monday vowing to "continue to fight for Brendan and the many other children who have been wrongfully convicted due to the use of coercive interrogation tactics" and maintaining he had "confessed to a crime he did not commit."
"Unfortunately, Brendan isn't alone," Nirider said. "Over the past 20 years, extensive empirical and psychological research has shown that children under 18 are between three and four times more likely to falsely confess than adults -- and yet the criminal justice system fails many of them. It's up to the courts to put an end to this."