Story highlights Michelle Byrom is on death row for a murder to which her son has confessed

If she's executed Thursday, Byrom will be first woman executed in state since 1944

Ex-prosecutor says he stands by verdict, as do Mississippi and federal appellate courts

Convicted gunman says he's innocent and that Michelle Byrom's son used him as pawn

The letter starts off like any normal letter from a son to his mother.

"First, let me say Happy M-Day, + I Love you."

The second sentence, however, reveals a darker history.

"Yes, the past is just that, the past, but certain decisions + choises (sic) are unforgettable and unforgiveable (sic)."

The letter was hand-written to a mother on death row, set to pay for a crime that her own son confessed to committing.

Mississippi Attorney General Jim Hood has requested that 57-year-old Michelle Byrom be executed by lethal injection Thursday for the 1999 murder of her husband, which prosecutors said she plotted. Edward Byrom Sr. was fatally shot in his home in Iuka, Mississippi, while Michelle was in the hospital receiving treatment for double pneumonia.

The state Supreme Court has the final say on executions and has yet to confirm the date or weigh in on the request.

If Byrom is put to death, she will be the first woman the state has executed in 70 years, but her advocates say there are many reasons she deserves a stay.

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Chief among them is the fact that Byrom's son has confessed not once, but four times, to killing his abusive father: in three jailhouse letters smuggled to his mother, and once in a statement given to a court-appointed psychologist.

In what's been called a "perversion of American jurisprudence" by Warren Yoder, executive director of the Public Policy Center of Mississippi, a jury has never heard any of Edward Byrom Jr.'s confessions.

This is because Byrom's defense attorneys, trying their first capital murder case, never had the confession letters entered into evidence. Byrom's son ended up taking a plea deal in exchange for a reduced sentence, testifying against his mother and pinning the plot on her.

In one explicit confession letter to his mother, Byrom Jr. detailed how he killed his father in a rage after his father called him a "bastard, no good, mistake, and telling me I'm inconciderate (sic) and just care about my self."

His father hit him for the last time that day, Byrom Jr. wrote.

"He slaps me, then goes back to his room. As I sat on my bed, tears of rage flowing, remembering my childhood, my anger kept building and building," the letter said.

Byrom Jr. retrieved a 9mm handgun -- a WWII weapon that belonged to his grandfather, according to the Jackson Free Press -- entered his father's bedroom, opened fire and fled, Byrom Jr. wrote.

Today, Byrom Jr. is a free man, living where he grew up, in Tishomingo County in rural northeastern Mississippi. He has found religion, according to a letter he wrote to his mother after her conviction, and his Facebook page says he studied fine arts at the New Orleans Baptist Theological Seminary.

The plan

Authorities say Byrom Jr., his mother and his friend, Joey Gillis, colluded to kill Edward Byrom Sr. in 1999. It was a murder-for-hire scheme, and Michelle Byrom was the alleged mastermind.

After the shooting, Byrom Jr. went to the hospital, told his mother what happened, then went back home to check to see if his father was still alive, according to a filing by the defense. When he found Byrom Sr. dead, he called 911.

Sheriff's officials arrived, questioned Byrom Jr., their main suspect at the time, and then Byrom Jr.'s best buddy, Gillis, because he had spent part of the day with Byrom Jr., according to a sheriff's official's statement during the trial.

Evidence at the trial included a statement to Sheriff David Smith, in which Byrom Jr. accused Gillis of the shooting and his mother of hiring his friend to kill his father. Gunpowder residue was found only on Byrom Jr.'s hands, never on Gillis', the evidence showed.

At trial, prosecutors presented a theory that Michelle Byrom was looking to collect on her husband's $150,000 life insurance policy and planned to pay Gillis $15,000 in exchange for the killing.

Yet in one jailhouse letter, Byrom Jr. wrote that he was inebriated and had fabricated a story in his statement to Smith.

"When they got me here, I gave them a bulls**t story after another, trying to save my own ass, but when David Smith started questioning me, and told me what happened, I was so scared, confused, and high, I just started spitting the first thought out, which turned into this big conspiracy thing, for money, which was all BS, that's why I had so many different stories," his letter read.

At the time of her husband's shooting, Michelle Byrom was under the influence of about a dozen drugs, several of which could have seriously impaired her judgment, according to an affidavit prepared by a pharmacology professor for the defense team.

Mississippi Highway Patrol officers questioned Michelle Byrom in the hospital -- not because she was a suspect, but because they had questions about the ownership of the murder weapon, according to the U.S. District Court.

Later that day, Michelle Byrom gave statements to Smith that included detailed accounts of the plan and the killing. Throughout the interrogations, Smith encouraged Michelle to protect her son, telling her that Byrom Jr. had already confessed to the murder-for-hire conspiracy and given details about his mother's involvement, according to court documents.

According to the state, while Michelle Byrom was heavily medicated, her doctor and a nurse were present during the initial police questioning and told authorities the drugs in her system should not affect her understanding of their questions and her responses.

Four out of five of the interviews conducted with her took place in the hospital. Two were thrown out because Michelle Byrom hadn't properly been advised of her rights, but subsequent incriminating statements she made stuck.

Deal struck

A Facebook photo shows Edward Byrom Jr. on a motorcycle.

Byrom Jr. cut a deal with prosecutors, and the night before Michelle Byrom's trial began in 2000, he agreed to testify against his mother in return for a lighter sentence.

Michelle Byrom's attorneys, who were trying their first capital murder case, withheld Byrom Jr.'s letters confessing to the crime, planning instead to use them against him on the stand, appellate court documents say.

Their strategy failed when prosecutors argued the letters couldn't be introduced as evidence mid-trial. Still, the defense was able to question Byrom Jr. on the stand about the content of the letters and statements he'd made admitting to killing his father.

On the stand, Byrom Jr. denied everything. He testified that Gillis was the killer and that Michelle Byrom had hired him. He also testified that once he and his mother realized police were intercepting their letters, they began to fabricate details, including his confessions, in hopes of sparing them both.

Michelle's subsequent appeals argued that failing to present the letters during trial hurt her chances of acquittal. After the jury found Michelle Byrom guilty, her attorneys, banking on a retrial, advised her to waive a jury sentencing and have the trial judge, Thomas Gardner, determine her penalty.

On November 18, 2000, the judge sentenced Michelle to death. Gillis, the alleged trigger man, never testified.

Gardner declined to comment on the case.

In 2006, Mississippi's Supreme Court voted 5-3 against Byrom's appeal, saying "counsel's performance did not prejudice" Byrom during the penalty phase of her original trial.

But in the dissenting argument, Justice Jess Dickinson wrote, "I have attempted to conjure up in my imagination a more egregious case of ineffective assistance of counsel during the sentencing phase of a capital case. ... I cannot."

The state supreme court review called it a "perplexing" choice by her counsel not to present certain evidence during trial.

Byrom Jr.'s plea deal saw him sentenced to 30 years in prison. He was released in August on earned-release supervision.

Facebook photos of Byrom Jr., who did not respond to CNN's requests for comment, show him posing on a motorcycle in one picture and with a child in another.

In a telephone interview with the Clarion-Ledger, Byrom Jr. told the newspaper he knew his mother would be executed. Asked if he shot his father, Byrom Jr. responded, "No, sir."

Goddess or witch

The Public Policy Center's Yoder says the prosecution portrayed Michelle Byrom as a witch in a part of the country where "people only have two categories for women: goddess or witch."

Michelle Byrom was "pressed to craft testimony worthy of a capital offense -- murder-for-hire, which makes a terrific story for a jury: 'Witch manipulated son by scheming,' " Yoder said.

Michelle Byrom was abused all her life, according to the defense.

Family members and doctors submitted affidavits detailing disturbing abuse. Michelle Byrom's siblings told the court their stepfather hit them for minor misbehavior and that Michelle confided that he'd sexually abused her. She left home at 15 and after a brief courtship moved in with Byrom Sr. He was 31 at the time.

Her husband allegedly continued to abuse her, even forcing her to have sex with other men, which he videotaped, according to court documents. When Byrom Jr. was born, Byrom Sr. started abusing his son, a "classic abuse pattern to enforce silence," Yoder said.

Despite these circumstances, former Assistant District Attorney Arch Bullard, who prosecuted the case, told CNN that Michelle was doubtless the leader of the murder-for-hire plot, and the conviction has stood throughout the legal process.

Although abuse was mentioned in the defense opening, Bullard said, those allegations were never backed up. There was no paper trail of abuse, no domestic violence arrest record, no record of hospitalizations. Instead, Bullard said, Michelle Byrom wanted a payout from her husband's life insurance policy.

"Not only do I think that she was the mastermind or part of the conspiracy to have him killed, so did the jury, so have all the appellate courts in Mississippi, and throughout the federal system," the former prosecutor said.

Bullard says he has "total faith in our judicial system," and while he still believes Gillis was the shooter, "it doesn't matter who the trigger person was. (Michelle Byrom) was intimately involved in the planning and execution of her husband."

Michelle Byrom's supporters argue that her capital murder conviction should be thrown out if Gillis wasn't the trigger man, let alone if Byrom Jr. killed his father in a fit of rage without conspiring with his friend or mother.

They also question why more value isn't placed on two circumstances surrounding the killing: Police never found gunpowder residue on Gillis' hands, and Byrom Jr. led police to the murder weapon.

In a rare interview, Gillis told CNN that he's innocent and that Byrom Jr. and prosecutors used him as a pawn. Gillis was released from prison in 2009 after serving time for conspiracy to commit capital murder and accessory after the fact -- charges to which he pleaded guilty in a deal after Michelle Byrom's sentencing.

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Gillis says he paid with his freedom as a result of his former buddy's betrayal.

During his eight years, 10 months and 15 days in prison, "they took all my rights away, and they had knowledge I didn't do it," he said.

He now has a family and says he can "forgive, but never forget." Gillis said Byrom Jr. tried to connect with him on Facebook after the two were released from prison, but Gillis ignored the request, essentially communicating that he had no intention of associating with his old pal.

Now a free man, he's angry with the system and wants to move on.

Last-ditch appeal

At the heart of Michelle Byrom's quest to spare her from lethal injection is the argument that she received ineffective counsel and that her son's confession to a court-appointed psychologist was never presented to a jury.

Her defense team also alleges the trial judge was aware of the confession but concealed the evidence in the guilt phase.

Though Byrom Jr.'s confessions weren't used during Michelle Byrom's sentencing phase, his confessions were the reason prosecutors allowed Gillis to plead guilty to lesser charges. The "offer of proof" presented by the prosecutor as part of Gillis' plea bargain stated Gillis was not the shooter, which doesn't jibe with the prosecution's trial theory that Gillis pulled the trigger and Michelle was the mastermind.

In his dissent, Justice Dickinson also noted that Michelle's trial judge didn't have the legal authority to issue a death sentence because a defendant must be "knowing" and "voluntary" in waiving their right to a jury sentencing in a capital case. Michelle Byrom's current attorneys say she was not "knowing" because her decision was based on erroneous legal advice from her trial lawyers.

A juror told the Clarion-Ledger, which printed some of Byrom Jr.'s confession letters, that while the letters showed the son was "very disturbed," she didn't believe they warranted a different verdict.

Bullard, the ex-prosecutor who told CNN the case stood out in his 20-year career because of the senselessness of the crime, said he stood by the original verdict.

"When you're trying a capital murder case, you make decisions based upon your preparations. There is a Sunday morning armchair review by the appellate courts that looks at what occurred. All courts have said that the error by the judge and the defense counsel doesn't outweigh the outcome of the case," he said.

Conversely, former state Supreme Court Justice Oliver Diaz Jr., who favored a new trial for Michelle Byrom when he was on the bench, told CNN that it's "atrocious" that her conviction has not been overturned.

"The majority of Mississippians support the death penalty because they think that people get fair trials and they think that they have competent attorneys representing them," he said. "In this case, she didn't have either one."​