A federal judge has overturned murder conviction of Brendan Dassey. Dassey was 17 when he was sentenced to life in prison for the murder of photographer Teresa Halbach.

Halbach was found dead in November of 2005.

In March of 2006, Dassey was charged as an accessory, after he confessed to helping his uncle, Steven Avery kill the photographer. Despite saying the confession was coerced, Dassey was convicted.

But in a 91-page decision Friday, a federal judge said investigators tricked Dassey into confessing his role in the murder, rape and torture of Teresa Halbach, using an interrogation of false promises.

"The honest person is the one who's going to get a better deal out of everything. You know how that works," said one investigator on the 2006 tape. "Honesty's the only thing that will set you free."

The court also questioned the exploitation of Dassey's low IQ.

"There's no question Brendan Dassey's case was weak," said defense attorney Jerry Buting. "They had nothing, nothing but the confession."

Buting knows the details of the confession.

He defended Avery and said it was obvious law enforcement was feeding Dassey all the facts. It just took the right level of the justice system to see it too.

"State courts are elected judges," Buting said. "Unpopular decisions are difficult for judges to make when they have to run for election."

So will this botched confession help Avery's appeal?

Buting believes the state will argue it didn't use the video in Avery's trial, so he should remain in prison. But, he said new evidence and incoming tips will soon reveal the truth both men are innocent.

"Brendan Dassey should be free and the state of Wisconsin should do so now," Buting said.

In light of the decision, Avery's new attorney Kathleen Zellner tweeted, "Brendan's opinion shows cops made up crime story. Steven's will show cops made up crime evidence."

Zellner said she visited Avery Friday and he was happy for Dassey. The state has 90 days to re-try Dassey, otherwise he'll be released from custody.