What to know about Texas death row inmate Melissa Lucio's case

A woman facing execution in Texas for killing her daughter is seeking clemency, claiming she was coerced into confessing to the crime.

Paramedics were called to Melissa Lucio's home in Harlingen, Texas, on Feb. 17, 2007, after her 2-year-old daughter Mariah Alvarez was found unresponsive and not breathing. Lucio told police Mariah fell asleep and did not wake up.

Lucio said that Mariah had fallen down a steep staircase during the family's move to a new apartment two days prior, but did not appear seriously injured, according to court records. Unable to be resuscitated, her daughter was later pronounced dead at the hospital.

Hours after Mariah's death, Lucio was interrogated by police for over five hours, according to her lawyers. She was especially vulnerable, her lawyers say, as she was grieving for her daughter, pregnant with twins at the time, and a victim of abuse and trauma throughout her life.

These conditions led her to be manipulated into admitting she caused her daughter's death despite Lucio asserting her innocence over 100 times throughout the interrogation, according to her lawyers.

"I guess I did it," police say Lucio told them.

Former Cameron County District Attorney Armando Villalobos, who was sentenced to 13 years in federal prison in 2014 for extortion in a case unrelated to Lucio's, described this statement as a confession during the trial.

After the trial, in which the prosecution said that her daughter's injuries could have only been caused by abuse, Lucio was found guilty of capital murder and sentenced to death. Her husband and Mariah's father, Robert Alvarez, was sentenced to four years in prison for child endangerment.

Nearly 15 years later, Lucio, 53, remains on death row at Mountain View Unit prison in Gatesville, Texas. Her execution is set to take place on April 27. She would be the first Latina to ever be executed in the state.

The U.S. Supreme Court in October declined to review a ruling from the U.S. Court of Appeals for the Fifth Circuit that upheld her conviction, paving the way for her execution.

The Innocence Project, a criminal justice reform nonprofit that aims to exonerate wrongly convicted persons using DNA and other evidence, joined Lucio's legal team soon after her execution was scheduled in January.

"The Innocence Project recognized the urgency that an innocent woman was headed for execution," Vanessa Potkin, director of special litigation for the organization, told ABC News.

Potkin said Lucio's presumed guilt "was a complete rush to judgment" spurred on by misunderstanding, a "highly manipulative and coercive" interrogation and faulty forensics.

"We've had her interrogation reviewed by leading experts in interrogation and false confessions. And they found that her statements are completely unreliable, that they're a mere regurgitation of the words that the officers were feeding to her over the course of five hours," Potkin said.

Lucio's legal team submitted an application for clemency to Texas Gov. Greg Abbott and the Board of Pardons and Paroles in March of this year, arguing an unreliable confession and "unscientific, false evidence that misled the jury into believing that Mariah Alvarez must have been killed by physical abuse, when the evidence is actually consistent with a conclusion that Mariah died from medical complications after a fall" based on the declarations of various experts.

The application also states that the state medical examiner who performed Mariah's autopsy was told that Lucio admitted to abusing the girl and was accompanied by two of the interrogating officers during the autopsy.

A juror from the trial has since expressed concerns and regret over the verdict, according to the Innocence Project.

"I think that's really significant that, you know, the individuals who heard the evidence against Melissa feel that the new evidence is so powerful that they may have voted differently in the case, and it just underscores the need for a court to consider the new evidence of Melissa's innocence," Potkin said.

An Innocence Project petition calling for a stop to Lucio's execution has surpassed its goal, having received over 185,000 signatures.

Abraham Bonowitz, co-founder and director of anti-death penalty advocacy group Death Penalty Action, said he believes that filmmaker Sabrina Van Tassel's Hulu documentary, "The State of Texas vs. Melissa," which follows Lucio as she appeals her case, speaks to her innocence. Death Penalty Action started the Free Melissa Lucio project shortly after Lucio was notified of her execution date.

"Our campaign is called Free Melissa Lucio because we don't want to just save her, we want her out," Bonowitz said.

Abbott's office, the Cameron County District Attorney's Office and the Texas Board of Pardons and Paroles did not immediately respond to ABC News' requests for comment.

The project's petition, asking Cameron County District Attorney Luis V. Saenz to rescind the execution, has received over 44,000 signatures.

"The ask is very specific. We're asking the governor and Board of Pardons and Paroles and the district attorney, which are the three [political] entities that can do something about this, to watch the film...because we believe anybody that watches this film will come away at least with doubt if not being convinced of Melissa's innocence," Bonowitz said.

According to Bonowitz, factors like ableism and racial and socioeconomic bias in the criminal justice system pose too much of a threat to warrant the use of the death penalty.

"When you get to this point, you find there's so many layers that most people aren't aware of and don't care about, frankly. They look at who's the victim, what's the accused accused of doing? Were they convicted? Okay, let's kill them. And that's as much as people want to know," he said.

"There's so much more to it that happens way before the crime."

The Free Melissa Lucio project has worked closely with John Lucio, Melissa Lucio's eldest son, as he advocates for his mother's exoneration.

He spoke in emotional support of his mother at a press conference on Friday held by civic engagement nonprofit Somos Tejas, Texas state Rep. Victoria Neave Criado and other Texas state legislators saying that his family "hasn't been the same" since her incarceration.

"My mother is an innocent woman. My mother was never the abusing woman -- the monster that the district attorney Armando Villalobos, former district attorney, made it seem like," John Lucio said.

"She was a good mother. She wasn't a perfect mother, but she made sure we were taken care of," he said.

Neave Criado who visited Melissa Lucio on death row earlier this week spoke at the conference about the bipartisan support her case has received. Eighty-three Texas representatives signed a letter asking that she be granted clemency.

"The fact that we are all here today and why almost 90 state representatives, the majority of the Texas House, have rallied behind this cause to save Melissa Lucio's life is because of the injustices in her case. It's because of the trauma that she has suffered all of her life," she said.

Michelle Lucio, John's wife who knew Melissa Lucio prior to her conviction, recalled the conversations with her during their visits in prison.

"She gets very emotional because no one believed her for so many years that she was innocent. You know? All she had was us," she said.

"I don't want to be in that room on April 27 to see her get executed," Michelle Lucio said.