Linda Carty has spent almost 20 years on death row after being convicted of the 2001 murder of her pregnant neighbour Joanna Rodriguez, with prosecutors claiming she was so desperate for a baby that she kidnapped the local and tried to steal her son – equipped with scrubs and scissors so that she could cut the infant out.

However, it turned out that 25-year-old Rodriguez had actually given birth four days beforehand, meaning she was abducted along with her young child, Ray. The new mother was then suffocated to death and found in the boot of Carty’s car.

In British Grandma on Death Row, we see presenter Susanna Reid travel to Texas to meet Carty as she continues to plead her innocence, despite substantial evidence against her.

Reid tells her: “A young woman, who had just – four days before – given birth to a precious baby boy, ended up dead in the boot of your car. And her newborn baby boy was discovered in your daughter’s car.”

As Carty nods in agreement, Reid asks her: “If you weren’t the one responsible, how did that happen?”

Carty, who holds British citizenship as St Kitts was a British colony when she was born there before emigrating to the United States, replies: “I don’t know for sure, because I wasn’t there. But I can truthfully say – and I can truthfully look you in the eye and tell you – that I had nothing to do with this crime.”

Carty maintains that she was framed her by co-defendants, who were drug dealers, as she had previously worked as an informant.

Even Carty’s daughter, Jovelle Joubert, believes she did not carry out the crime, saying: “That’s just crazy.”

But while Lynn Hardaway, former Harris County Assistant District Attorney, says she doesn’t have ‘any doubt’ that Carty is guilty – saying ‘all the evidence was consistent and had her as the ringleader and orchestrator of the whole offence’ – other top legal experts point out flaws in the argument.

In the documentary, we also hear from barrister Hugh Southey, who tells Reid that there is actually no DNA evidence to link Carty to the crime.

Reid asks him: “If Linda put a plastic bag over Joanna’s head, presumably there would be forensic evidence – DNA evidence – to show that?”

Southey replies: “Well, there is no DNA evidence. It’s surprising, given what’s alleged, that there is no DNA evidence, but to be fair, many criminal cases lack DNA evidence. But that’s an important part of the context, in one sense, because it means that you rely on the evidence of individuals, and individuals are never necessarily the most reliable people – partly because people deliberately lie, but partly also because our memories are faulty.”

A press release from ITV says Carty’s case is by no means ‘straight forward’, as there are ‘many questions over the validity of the witnesses who testified against Linda at her trial, as their stories have changed since Linda’s conviction’.

Despite several applications for appeal, Carty remains behind bars awaiting the death penalty.

Watch British Grandma on Death Row with Susanna Reid on Tuesday 22 March at 9pm on ITV or catch up on ITV Hub.