7NEWS Spotlight sits down with accused murderer Lisa Cunningham in Arizona as she prepares for trial

It’s a calculated risk to put an accused killer in the witness stand, even more so to air their defence in the court of public opinion before a trial’s even started.

Tonight, Australian mother and accused murderer Lisa Cunningham will do just that.

Marched from her two-by-three-metre prison cell into an interview room on the outskirts of Phoenix, Arizona, Lisa smiles nervously as she sits in front of a camera for the first time since her arrest.

She’s had almost eight years to mount a defence for a murder she says she didn’t commit.

Her grey walls are adorned with children’s drawings, photographs and reams of legal documents. When she’s not busy baptizing other prisoners, Lisa’s preparing for this trial like her life depends on it. Because it does.

Arizona prosecutors may have dropped the death sentence they’d been pursuing for seven years, but they’ll still argue she should spend the rest of her natural life behind bars for allegedly killing her step-daughter.

“The only way you’re getting out is in a pine box,” her lawyer, Eric Kessler tells me in tonight’s exclusive interview, airing on 7NEWS Spotlight.

The wheels of justice turn slowly in America, but it’s been an agonizingly long wait for this Adelaide-born woman to have her day in court.

It was 2018 when I first travelled to Arizona and saw Lisa in a Phoenix courtroom dressed in orange prison garb. Swap her handcuffs for a school bag and she strikes you as the average Australian mum.

Except Lisa is accused of the most heinous crime, facing a first-degree murder charge over the death of her seven-year-old step-daughter Sanaa.

The case is as heart-wrenching as it is nuanced.

Having met Lisa’s relatives, and now Lisa herself, it’s hard to comprehend how this blissful blended family blew up in the most tragic way, with five surviving children split up and re-homed, and two parents languishing in separate prisons.

Sanaa had been suffering from Schizophrenia for months and her mental decline was well-documented. The Barbie-loving girl spent her final weeks living in torment.

Whether she died as the result of a medical tragedy - with sepsis and pneumonia - or at the hands of her Australia step-mother will be for a jury to decide.

What’s clear is there’s no justice while Lisa spends her days inside Estrella Women’s Jail without conviction. It’s among the harshest jails in the country and meant to be a temporary holding facility, but Lisa is now among the longest held women there.

The days are monotonous, stifling hot and peppered with violent outbursts from other prisoners. Housed alongside some of the country’s most notorious killers, Lisa’s had no visitors except her lawyer in the eight years since her arrest.

Sitting behind a zoo-like caged barrier, with cameras rolling, Lisa leans in.

She’s adamant she has nothing to hide and when asked bluntly if she killed her daughter, she snaps back: “Nobody killed Sanaa. It’s an unfair question”.

Watch Lisa Cunningham on 7NEWS Spotlight tonight at 8pm on Seven and 7plus.