Hannah Overton asked me to give her five kids a hug for her, knowing that I was going to see them the next day. She gets to see them once a month through a glass window in the visiting area of the women's prison where she's been serving a life sentence for murdering her adopted son Andrew. But for all these years, there has been a dogged group of supporters - including her church community - that believes steadfast in her innocence.

When she first arrived, the prison guards predicted that her husband, Larry, would slowly stop visiting and eventually divorce her within a year. Five years later, they all know him by name because he drives 300 miles every weekend - after being a single father of five all week long - to visit the woman he first fell in love with when they were teens.

Hannah was convicted five years ago today and sentenced to life in prison.

It all began on a normal day when her foster son Andrew, who's biological mother was a Meth addict, had a temper tantrum then threw up and said he felt cold. Like harried mothers of many kids, she comforted him, put a blanket around him and even drew a bath to warm him. But Andrew's condition deteriorated and they drove him to the hospital. He died the next day of salt poisoning.

Mother of five Hannah Overton, in prison on a life sentence, believes she will be set free. (Todd Yates/Corpus Christi Caller-Times/AP Photo)

We at "20/20? found Andrew's pediatrician who said he was not a typically developing child. According to Hannah and her supporters, he'd eat a jar of pickles or a dozen eggs; his pre-school teacher said he even ate things out of the trash. Another expert I spoke to said he believed, based on research into other salt poisoning cases he'd found, that Andrew most likely ate something salty voluntarily because of a disorder called pica-where people eat non-edible items.

But Hannah was found guilty of capital murder because the jurors felt she hadn't called 911 or gotten medical treatment for him soon enough. The expert we spoke to felt that very few people, even medical experts, could have realized what was going on inside little Andrew's body. And he added that even if the Overtons had gotten Andrew there earlier, he could not have been saved. Prosecution experts disagreed.

This is a story that keeps me up at night.

Five years later, there are serious allegations of misconduct against the former prosecutor in the case. Hannah's lawyers say Sandra Eastwood improperly withheld evidence that would have helped Hannah. Even Eastwood's own co-counsel questioned her judgment in testimony last April.

She has denied wrongdoing and disciplinary tribunals have declined to press charges after investigating. Every appeal thus far has failed to convince a court of any wrongdoing.

But Hannah Overton is still asking for her case to be reviewed. Meanwhile, her five children are growing up without their mother. They are polite kids who are still home-schooled by church friends and they all have a firm belief in their mother's innocence.

Recently, I asked Hannah again if after all this, "Do you ever regret trying to adopt Andrew?" She didn't pause for a nano-second.

"Absolutely not. Never," she said. "The time that we had with him (meant) the world to us. We loved him."