28-year-old Dassey, who was 16 at the time of the murder, told Manitowoc County officers that he had helped his uncle, Steven Avery, rape and murder the freelance photographer after being interrogated four times in 48 hours.
He is currently serving life imprisonment for murder, sexual assault and mutilation of a corpse in connection with Halbach's death.
CNN reports that Dassey's lawyers have maintained that his constitutional rights were violated adding that he was convicted based solely on the confession and with no physical evidence. Court papers included accusations against his interrogators of feeding him the “right” answers despite displaying “significant intellectual and social limitations.”
Despite this, a panel of judges ruled against Dassey's appeal maintaining that he spoke “freely” when confessing to the crime.
His attorney, Laura Nirider, has vowed to “continue to fight for Brendan and the many other children who have been wrongfully convicted due to the use of coercive interrogation tactics.”
Nirider added: “Unfortunately, Brendan isn't alone. 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.”
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