Story highlights Dassey's lawyers argued his confession was coerced

The appeals court overruled a federal magistrate's decision

(CNN) A federal appeals court ruled Friday that the confession given by Brendan Dassey, a key figure in the Netflix "Making a Murderer" series, should not be thrown out.

The decision from the US Seventh Circuit Court of Appeals reverses a federal judge's ruling and means Dassey's life sentence will remain in effect.

Dassey, now 28, was convicted in 2007 in the slaying of Wisconsin photographer Teresa Halbach. In 2005, Dassey, then 16, confessed to authorities that he assisted his uncle, Steven Avery, in raping and killing Halbach. Her charred remains were found on Avery family property in Manitowoc County.

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Dassey later recanted his confession. His lawyers appealed through the state court system and then into the federal system, contending the confession was coerced. Court papers also raised the issue of Dassey's IQ, described as being in the "low to borderline" range.

On Friday, the full Seventh Circuit Court of Appeals ruled 4-3 that the confession should stand.

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