Linda Carty has lingered on Texas death row for more than a decade, convicted of plotting the murder of her neighbor, Joana Rodriguez, in order to steal Rodriguez's newborn baby in 2001.

Her previous appeals have all failed - despite international protests over the fact that her Harris County-appointed attorneys spent only two weeks preparing for her capital trial. Her conviction rested on the prosecution's theory that Carty, a former school teacher from the Caribbean island of St. Kitts, directed three men with criminal histories to storm the victims' apartment, steal $1,000 and carry out the mother and child's abduction at gunpoint.

Now she's gained support for a new appeal from two unlikely sources: the DEA agent for whom she was once a confidential informant and a star prosecution witness who has now recanted.

In affidavits separately supplied to Carty's current defense team in 2014, the agent and two of Carty's co-defendants allege that Harris County prosecutors crossed ethical boundaries and threatened them to ensure Carty's conviction.

Retired DEA Special Agent Charles Mathis, in his affidavit, specifically accused Connie Spence, the lead prosecutor on the case, with threatening to cross-examine him in open court about "an invented affair that I was supposed to have had with Linda." Mathis insists that allegation was false, but worried that it could have clouded his law enforcement career if Spence had carried out her threat in a capital murder trial that generated considerable publicity.

Charles Mathis 2014 Affidavit

The affidavits from two of Carty's co-defendants accuse Spence and another prosecutor of threatening them with a death sentence and of feeding them stories designed to "nail" Carty.

The allegations of prosecutorial misconduct have been presented as "new evidence" in support of Carty's effort to win a hearing, a request now pending in the Texas Court of Criminal Appeals that was filed by Michael Goldberg, a Baker Botts civil attorney who has stuck with the case for more than a decade pro bono.

Front-page case

Carty holds British citizenship, and her case has generated a documentary film, front-page news stories in London newspapers and appeals from celebrities, like Bianca Jagger. In an amicus brief, the British government has argued the court should order a hearing so that a Harris County judge can consider whether Carty's death sentence came only after prosecutors coerced key witnesses to testify.

Carty was the last death penalty trial for defense attorney Gerald Guerinot, who over the years saw 20 clients condemned to death row - a number described by the American Bar Association Journal as a "possible record" for any capital attorney in modern times.

The Harris County DA's office has filed no response to Carty's latest filings, and a spokesman declined comment on specific allegations against Spence, who heads the county's major offenders, organized crime and major narcotics prosecutions, as well as against Craig Goodhart, another senior prosecutor who worked on the case.

Assistant District Attorney Roe Wilson, who handles capital appeals for the office, said she is waiting for the court's decision before conducting any investigation.

"If the Court of Criminal appeals returns the writ to the trial court, the State will thoroughly investigate and respond to all claims," Wilson said via email.

Mathis, through an attorney, declined an interview.

Carty was a popular teacher in her native St. Kitts before she moved to Texas and briefly studied at the University of Houston. As a newcomer, she dated a man who turned out to be a drug dealer, and during that relationship, she became an informant for the DEA, according to information in court filings.

She passed a background check and over the years got paid for providing a series of valuable tips, Mathis said in his affidavit. Carty is the mother of an adult daughter and now a grandmother. But years after the birth of her daughter, she suffered several miscarriages, and Harris County prosecutors argued that by 2001, she had become obsessed with the idea of getting a baby to patch things up with her common-law husband. The pair lived in the same apartment complex as Rodriguez, 25, and her family.

Carty was not present during the home invasion or kidnappings, but prosecutors claimed she planned the so-called "lick" to get the child she so desperately wanted.

The three masked men who abducted Rodriguez and her son all had criminal records - one had previously been convicted as a killer in a drive-by shooting. Rodriguez was later found dead in the trunk of a car: she'd been tied up, dumped there and asphyxiated. Her 3-day-old son was rescued from a car parked nearby.

Chris Robinson Affidavit

In the end, only Carty was prosecuted for capital murder. She got a death sentence in 2002.

Jurors were convinced in part by the testimony of a co-defendant, Chris Robinson. But Robinson now claims in his 2014 affidavit that prosecutors threatened him to testify that he saw Carty put a trash bag over Rodriguez's head when Rodriguez was in the trunk. "In fact, I did not see Linda Carty putting the trash bag over Johanna (sic) Rodriguez's head," he said. That story was fabricated by two Harris County prosecutors who coached him prior to trial, Robinson said.

"When we were rehearsing I would say the story back to them they would stop me and add something in or take it out then make me keep going. They would stop me by saying 'Wait, wait, this is what happened,' " he said in his affidavit. Several months after the trial, records show, capital murder charges were dropped against Robinson, though he was prosecuted for kidnapping and received a 45-year sentence in November 2002.

'This just wasn't true'

Another co-defendant, Gerald Anderson, said in the affidavit he supplied that the same prosecutors told him he needed to take the stand and say that he was present when Carty "was making the plan to take the lady and the baby. This just wasn't true."

Ultimately, Anderson did not testify.

Mathis, who served in the DEA for three decades, said Carty asked police to call him when she was questioned about her neighbor's disappearance because they had worked together for years. He said he quickly realized that she'd been targeted as a suspect, while Carty appeared to assume she was only helping officers to rescue Rodriguez and her child from men who Carty claimed had "borrowed" her car. Mathis argues in his affidavit that prosecutors fabricated their theory to implicate Carty as a criminal mastermind. Mathis insists that Carty was "afraid" of her co-defendants and incapable of committing or plotting a murder.

Carty's arrest came in the final years of Mathis' career with the DEA. Back in November 1972, Mathis had been hand-picked to be part of the first class of DEA special agents. For most of his career, he worked in the Houston office on drug trafficking cases, busting rings involving everything from Caribbean dealers to Colombian kingpins. Still, Mathis said he was shocked as he saw how HPD officers aggressively questioned Carty without ever reading her Miranda rights. Mathis said he listened as Carty provided an address where she believed the men might have taken Rodriguez and the baby.

He said officers did not immediately respond to that tip. "I urged HPD to go to the location and see if they could recover the mother and the child. I understand now that it was not known at this time whether either ... were alive," he said. Instead, police seemed fixated on obtaining a confession from Carty, he said. They took her into a smaller room and for hours, they continued to shout at Carty, screaming inches from her face, though Carty never confessed, according to Mathis' affidavit.

"I had been a DEA agent for a long time and seen some aggressive tactics, but I had never seen anything like this," he said. "I knew what they were doing was not appropriate or within the rules and I did not want to be involved in something like this."

Later, Spence threatened him with the allegation of an affair, he said.

"I was shocked when (prosecutor Connie) Spence said this. I was (and still am) in a very happy marriage. Moreover, DEA agents should not have such relationships with their confidential informants. But beyond this I was and still am very proud of my reputation as a law enforcement officer with integrity and who did things right," Mathis said. "I never had an inappropriate relationship with Linda Carty. Spence entirely invented the whole concept. ... I felt Spence was threatening and blackmailing me into testifying."

Attorney called 'undertaker'

Carty's previous round of appeals were primarily based on the argument that Carty's first appointed attorneys failed in their duties and violated her constitutional rights. They did not advise her common-law husband that he might be able to decline to testify; nor did they contact the British government for assistance.

Guerinot and his co-counsel were appointed to replace Carty's hired attorney only a month before trial and spent two weeks preparing, according to a 5th Circuit opinion. His relationship with Carty was poor; they barely spoke. She called him an "undertaker."

The 5th U.S. Circuit Court of Appeals found Carty's representation deficient in a 2009 ruling. But that court declined to give Carty a new trial, though it ruled her defense team erred by failing to question her common-law husband. The court found that omission "did not prejudice Carty's defense."

Since Carty already has lost appeals at both the state and federal level, the top Texas criminal court must decide whether the new information is extraordinary enough to merit an unusual round of state court reviews.

"The UK believe that this new evidence brings to question serious concerns for the human rights, fair trials and access to justice by Ms. Carty which the Texas courts should have an opportunity to consider on its merits," the UK's brief says.