But plans seemed to have changed, with Zellner saying she will be taking 'full and complete representation' of Avery

Earlier this week, one of Avery's former defense attorneys, Dean Strang, said there was a possibility he could represent Avery again

Zellner said in a statement that she will be assisted by the legal director of the Midwest Innocence Project

that she will assume full representation of Steven Avery's pending criminal matters

The family of Steven Avery have confirmed to Daily Mail Online that Kathleen Zellner would be taking on his case and said they were confident she could set him free.

Chicago-based Kathleen Zellner will work with Midwest Innocence Project to represent Avery in pending criminal matters.

Earlier this week, one of Avery's former defense attorneys, Dean Strang, said that he could possibly represent Avery again. Avery has had no lawyer since his last appeal failed.

But Zellner has said she will be taking 'full and complete representation' of the 53 year old.

Speaking from her home in Two Rivers, Wisconsin, his mother, Dolores Avery, praised the Chicago-based attorney as she continued to assert her son’s innocence after he was sentenced to life without parole for the murder of Teresa Halbach in 2005.

The 78 year old said: ‘She's supposed to be really, really good.

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New Representation: Attorney Kathleen Zellner announced on Friday that she will take assume full representation of Steven Avery's pending criminal matters. Zellner said in a statement that she will be assisted by the legal director of the Midwest Innocence Project

Life without parole: Steven Avery on his way to be sentenced in June 2007 for the murder of Teresa Halabch. Two years later he said he believed his brothers Earl and Charles could have murdered her

Convinced: Dolores Avery believes the new Netflix series will lead to a fresh trial for Steven, at which he can prove his innocence. She said she believes Zellner is 'really, really good'

Another source close to the family told Daily Mail Online: ‘I know this lawyer will do a good job, I know she will.

‘She has got 18 post-conviction victories and that’s the kind of person we need. We’re on a time limit here. I feel so strongly about her. She’s the one that’s going to get him out.’

Zellner's law firm released a statement about taking over the case on Friday evening.

'The Law Firm of Kathleen T Zellner and Associates PC is pleased to announce that it will be assuming the full and complete representation of Steven Avery in all of his pending criminal matters,' the statement read.

It continued: 'Ms Zellner's firm will be assisted by local Wisconsin counsel Tricia Bushnell. Ms Bushnell is the Legal Director of the Midwest Innocence Project. The Zellner Law Firm is looking forward to adding Mr Avery to its long list of wrongful conviction exonerations.'

Zellner has previously freed wrongly convicted prisoners, including Mario Casciaro who was found guilty in the 2002 killing of grocery store co-worker Brian Carrick during a 2013 trail.

Implicated: Charles (left) and Earl (right) Avery were named in 2009 appeal documents as possible suspects in Teresa Halbech's murder by their own brother. But their mother says all three are innocent

Victim: Teresa Halbach was murdered in 2005 and last seen at the Manitowoc County, Wisconsin, car yard belonging to the Avery family. Steven - who spent 18 years in prison for a crime he did not commit - was convicted of her murder, along with his nephew Brendan, who was 16 at the time

The news of Zellner taking on the case comes after Dolores Avery told Daily Mail Online that she believes victim Teresa Halbach's brother might have had something to do with her murder and said she was convinced of all her sons' innocence after Steven had earlier pointed the finger at his two brothers.

Dolores Avery, 78, addressed the issue for the first time with Daily Mail Online after Steven Avery filed legal documents in 2009 suggesting his brothers' involvement.

In court papers, Steven Avery, who had just been sentenced to life without parole, claimed that his two brothers, Charles and Earl Avery may have murdered the 25-year-old photographer whose last known whereabouts were a visit to the family's auto salvage yard on October 31, 2005. The legal documents were originally obtained by TMZ.

When asked about Steven's 2009 filing and the potential involvement of her other sons by Daily Mail Online, Dolores sprang to the defense of all three.

She said that Steven may have been extremely desperate about being sent back to prison after he was freed in 2003 on DNA evidence following 18 years in jail for a rape he did not commit.

She said: 'He wrote that [legal document] when he was prison, maybe he felt he had to do something. But it wasn't anything to do with them [Earl and Charles Avery].'

Alternative theory: Dolores Avery tells Daily Mail Online of Teresa Albach: 'They say her brother [Michael, right] might have had something to do with it'

Speaking from her home on the outskirts of Two Rivers, Wisconsin on Thursday, the 78-year-old grandmother hopes that renewed interest in Steven's case will help free him.

She has watched the entire Netflix series and said that although the attention has been difficult for the family to cope with, she was pleased to have taken part in the documentary.

Avery, 53, is currently serving life without the possibility of parole for the murder of Miss Halbach in 2005.

His nephew Brendan Dassey, then 16, was also found guilty of her murder and sexual assault, and sentenced to life in prison with the possibility of early release in 2048.

Both men claim that they are innocent. Dolores told Daily Mail Online: '[The series] better make a difference.

'I think Steven will get a new trial. I don't know what it will take but I hope it comes out with the truth instead of a bunch of lies.'

Steven Avery had initially served 18 years for rape before being exonerated by DNA evidence in 2003.

Two years later, while Avery was suing Manitowoc County for $36million over wrongful imprisonment, he was arrested for the murder of Miss Halbach, whose last known whereabouts were a visit to the family's auto salvage yard on October 31.

Life sentence: Brendan Dassey was 16 when Teresa Halbach was murdered. He was sentenced to life. His grandmother, Dolores Avery, reveals that he has achieved his high school diploma behind bars

Avery's story is the subject of a ten-episode series, released last month, which has captivated viewers around the world.

Jerry Buting, who defended Avery in his murder trial, has said that the hit 10-part series has sparked an ‘enormous outpouring of support’.

As a result, scientists from all over have contacted him to suggest different ways that evidence can be presented to ‘demonstrate the innocence’ of the show’s subject.

However, all of Avery’s appeals are over and despite petitions demanding his release, Buting says the only way to free him would be with newly discovered evidence.

‘He is still in prison. He’s in prison for life. His appeals are over,’ Buting told BBC’s Today. ‘Which means that if he is to have any justice at this point it’s going to have to be because of newly discovered evidence, things of that sort.’

But he added: ‘There is something that can be done about it. We are getting an enormous outpouring of support. We’re getting new leads – factual leads that can be followed up.

‘Scientists from all over the world have been contacting us with different approaches to present scientific evidence that can be newly discovered evidence that would demonstrate his innocence.’

Buting and his fellow defense attorney Dean Strang are presented as the unrelenting protagonists on the series, working to prove that Avery was framed for the murder of 25-year-old photographer Teresa Halbach in Manitowoc County, Wisconsin, in 2005.

However, authorities involved in the case insist the series is biased and omits crucial facts that led to Avery and Dassey being found guilty of Halbach’s murder in 2007.

Filmmakers Laura Ricciardi and Moira Demos have stood by their work, which spans ten years and largely focuses on the defense and the perspective of Avery and Dassey’s family.

Buting too insists that the filmmakers were fair in their portrayal of the case.

Crime scene: The Avery scrap yard was searched for days by police after the discovery on it of Teresa Halbach's car

Family home: Dolores Avery and other members of her family still live at the scrap yard, with Dolores living in this home. Steven's trailer still lies empty, awaiting the return his family hope for

Commenting on claims the series leaves out key evidence, he told the BBC’s Today program: ‘Well that’s not true at all. They offered the same opportunity to the State to participate and they chose not to.

‘They included the majority of the State’s case the important pieces are in the movie.’

He added: ‘There’s really only one tiny bit of DNA evidence that ever linked her to his residence or his garage and that was a contaminated test that frankly should have been thrown out. That’s clearly set forth in the series.’

Ken Kratz, the former Calumet County district attorney who prosecuted Avery, is one of the series’ critics, saying Netflix should not have billed the series as a documentary.

More than 100,000 people have signed an online petition for Avery and Dassey to be exonerated although Wisconsin Governor Scott Walker stated on Wednesday that they will not be pardoned.

The White House yesterday turned down a similar petition on the grounds that presidential clemency powers only apply to federal prisoners.

Dolores does not think there is chance for her son to be treated fairly in Manitowoc County.

'He won't get a fair trial around here, if he gets one. Somebody said that it could be in Texas, that's a way from here,' she said.

The renewed interest in Steven's case, which has gone past the point of his last appeal, has also reignited a spark of hope in him, according to his mother.

She said: 'I think he's happy and I hope that he's going to be getting out. Steven gets a lot of letters now and I think Brendan is getting them too.'

Dolores, who has received cards and flowers from as far as Spain, said that she hoped the documentary might change local opinions.

She said: 'In the town everyone looks at you but they don't say anything. People are being kind, better than they were before.

'Before a lot of people looked at you or else they said something. I always told them, my son and my grandson are innocent.'

She shared early memories of Steven with Daily Mail Online at her home, filled with family photographs. 'He was just a boy – boys ain't all angels, you know.

'He was okay, he used to work on cars and cleaning up the garage here. That whole garage he used to work on when it needed cleaning, he didn't like it all messy.'

The 78-year-old said that her son wasn't much into partying 'not any more than any other kid'.

Dolores believes the police have had a grudge against him since he was a teenager.

'They are crooked people those cops in Manitowoc - and in Calumet [county] I heard too.'

She hopes that investigators will reopen the Teresa Halbach murder case.

Scrap: The Avery family business of auto salvage means the yard is full of cars. One of them fatefully turned out to be the RAV4 driven by Teresa Halbach

'I wish they would find the person,' she said. She believes that her son had been framed for Miss Halbach's murder.

'I don't know [who is behind this], the cops I bet,' she said.

She spoke scathingly of Ken Kratz, the district attorney drafted in from Calumet County by Manitowoc County to prosecute Steven in order to quash any suggestion of bias.

'He was just as crooked as the rest,' she added.

The 78-year-old said she didn't remember much from the day that Teresa Halbach visited the family's auto salvage yard in order to photograph a minivan for AutoTrader magazine.

'I don't remember it much,' Dolores said. 'She was here but then she left, that's what I know. They say her brother [Michael Halbach] might have had something to do with it.'

Teresa Halbach was reported missing on November 3, 2005, and police focused on Steven Avery, believed to be the last person to see her alive.

For nine days, Wanitowoc and Calumet County Sheriff's Department searched the Avery property along with teams of volunteers which included Teresa's immediate family.

The Avery family were forced to move to their cabin 90 miles away.

Dolores said: 'My Medicare medicine was left behind on the kitchen table, I couldn't even come back and get it.

'The Manitowoc Sheriff's Department told me to go to the doctor again but I said I can't go again, I was just there. After a while, they got it for me.

'They were in my whole house, the basement, everywhere. I think all of them [police and volunteer searchers] were all over.

'They took my sheets off the bed, good thing I had another pair of new ones. I couldn't tell you if anything went missing from the house.'

She added: 'We never knew what was going on. We couldn't come back home for eight days.'

Dolores doesn't believe that the police interviewed anyone other than Steven.

'They said they had him, so that's how it went,' she said.

On November 8, Teresa Halbach's car key was found in Steven Avery's bedroom along with her car and charred bones found at the salvage yard.

None of Halbach's DNA was ever discovered inside of Avery's home, where the prosecution claimed she was tied to the bed, raped, stabbed and shot in the head.

On November 11, Avery was charged with murder and has been behind bars ever since.

Dolores described an incident which left her frightened soon after her son's arrest.

She said: 'I was in the living room one night at nine o'clock and the squad car was out there with a spotlight on, shining in my patio door, when I was sitting in my nightgown. They [the police] are troublemakers.

Steven Avery's trailer, a short distance from his parents' home, still lies empty.

Dolores said: 'They ripped Steven's whole house apart. They ripped the walls apart and the bed. No one could live there, the plumbing is all frozen up and broken. It's a piece of junk now.'

The auto salvage yard also lies quiet with the number of customers dwindling since Steven was arrested a decade ago.

Dolores said: 'Things are not so good with the business, it has slowed way down compared to what it was before Steven was arrested.

Brothers: Charles (left) and Steven Avery seen together in 2003, shortly after Steven's release from custody when he was cleared of the sexual assault of Penny Beernsteen, for which he spent 18 years wrongly imprisoned

First victim in series: The sexual assault of Penny Beernsten led to Steven Avery being wrongly jailed for 18 years, the starting point for Making a Murderer

Horror: The remains of Teresa Halbach were found in the 'burn pit' of the Avery salvage yard in February 2007, after she had gone missing

'Maybe some believe in that stuff that he's guilty - but he's not.'

Most of the family have rallied around each other. 'They are all coping alright I think,' Dolores said. 'But it depends on who they are though.

'Maybe they don't want to talk to the outside world but we always talk.'

Dolores said she and her husband Allan, 80, remain in good health despite the strain of Steven's conviction.

She said: 'I'm pretty good but I've got to be, I suppose.

'Allan is okay but he hates what's going on with Manitowoc County. They are so crooked.'

Recently, Dolores and Allan have not seen their grandson, Brendan, because it is difficult for them to get up the stairs at Green Bay Correctional Facility where he is serving his life sentence.

Dolores believes Brendan, now 26, is coping fairly well and had completed his high school diploma while in jail.

But she shared her concerns for her daughter, Barbara Tadych, Brendan's mother.

Dolores said: 'Brendan is doing pretty good compared to his Ma. He was only 16 and now he's 20-something already.'

Making A Murderer casts doubt on Dassey's testimony during the trial. He was 16 at the time and told authorities that he helped his uncle commit the murder.

He's studying his own case, I think he'd be a better lawyer than the lawyers are. Some of his lawyers have been no good. He reads his scripts to see what he can do and goes to the library. Dolores Avery on her son Steven's life behind bars

Dassey, who reads at a fourth grade level, told police he helped Avery rape, stab, shoot and dismember Halbach.

Dassey confessed to sexually assaulting Halbach and cutting her throat on his uncle's orders. He later said the confession was coerced.

Dolores said that her grandson was angry about how he had been treated by the judicial system.

'I think he knows now what happened,' she said. 'He was a young kid, a tiny kid, and he isn't anymore.

'He was always very quiet. He used to sit here and play the Nintendo.'

A lawsuit for Dassey has been taken to federal court in Wisconsin by Northwestern University's Center on Wrongful Convictions of Youth.

The suit claims that Dassey was illegally imprisoned in 2005 and asks that Dassey be granted a writ of Habeas corpus, meaning his case must be re-examined.

A decision is likely to be made in the next year.

Dolores said: 'Brendan's got a lawyer for that now. He has a chance and I hope it gives Barb hope.'

Meanwhile, she and her husband continue to regularly visit Steven at Waupun Correctional Institute, a 180-mile round trip from their home.

Dolores said: 'It's much closer than the other prisons he has been in. We get up once every week and a half, depending on the roads now.

'We used to drive all the way to Tennessee. We used to leave on Friday morning and stay until Sunday. We went once every two months or so. We were younger then.

'We can hug him but only when we get there and when we leave. I suppose all the prisons are like that.'

Avery, who has an IQ of 70, has spent a number of years studying his case in the prison's law library after the failure of his Supreme Court appeal meant he was left without a lawyer.

Last year, Avery petitioned the circuit court without an attorney but the motions were denied in November.

Dolores said: 'He's studying his own case, I think he'd be a better lawyer than the lawyers are. Some of his lawyers have been no good.

'He reads his scripts to see what he can do and goes to the library.'

Avery's parents often visit with Steven's girlfriend, Sandra Greenman, who initially came into contact with him after writing a letter of support when he was convicted in 2007.

After a total of 25 years in prison, Steven Avery continues his fight to be freed as an innocent man. His mother remains similarly unwavering in her belief in her son.