By Christina Carrega, CNN

(CNN) -- Sabrina Smith was only 17 when a predominately White Mississippi jury convicted her in 1989 for fatally beating her 9-month-old son.

"The judge said, 'we sentence you to death by lethal injection. May God have mercy on your soul,'" she recalled. "All I could say was, 'may God have mercy on your soul because you don't know what you just did.'"

Eyewitness testimony and medical evidence that was produced during the first trial would later reveal that Smith's baby died from kidney disease.

Still, Smith served six years in prison, including nearly three years on death row. Clive Strafford Smith, an attorney and a co-founder of Reprieve, a nonprofit legal organization, was able to get her conviction overturned and, after a second trial, she was acquitted of all charges.

"State-sanctioned murder is not justice, and the death penalty, which kills Black and brown people disproportionately, has absolutely no place in our society," Massachusetts Rep. Ayanna Pressley said in a January letter to then attorney general nominee Merrick Garland. "Ending the federal death penalty -- which is as cruel as it is ineffective in deterring crime -- is a racial justice issue. It's time to truly move our country in the direction of justice and healing."

Legal experts and advocates say Smith's case is emblematic of the larger issues that plague the criminal justice system, especially for Black and brown people. In Smith's case, she was sitting on death row before she was granted a new trial to clear her name.

A recent study by the Death Penalty Information Center (DPIC) revealed that in two-thirds of overturned death row convictions, official misconduct, perjury or false accusations played a role in 70.7% of Black and 93.8% of Latino exonerees' cases.

The DPIC announced in February that since the 1970s, 185 people, who received death sentences, were wrongfully convicted. Among them are: 66 White men and one White woman, 16 Latinos, one Native American or Alaska Native, two identified as other and 97 Black men and one Black woman -- Smith.

Former death row inmates, who were convicted of crimes they did not commit, have been using their voices to reform the justice system. They've joined hundreds of lawmakers to call on President Joe Biden to reform the justice system and abolish the controversial death penalty.

Smith, now 50, has dedicated her life to that cause.

Appealing to a new administration

During his campaign, Biden pledged to reform the criminal justice system, including the death penalty. The abolishment of the controversial sentence is listed within his plans of "Eliminating Racial Disparities and Ensuring Fair Sentences" section.

Prior to former Attorney General William Barr reinstating the federal death penalty in July 2019, there hadn't been any executions scheduled since 2003. The Justice Department has repeatedly declined to comment on why the moratorium was lifted.

Legal attempts to stop executions were exhausted by July 2020. Under the watch of former President Donald Trump, the lethal injection deaths of 12 men and one woman went according to plan and ended within days of Biden's inauguration in January.

Of those executions, the circumstances of the cases for Brandon Bernard and Lisa Montgomery drove anti-death penalty advocates, lawmakers, civil rights leaders and celebrity Kim Kardashian West to try and convince Trump to stop these proceedings.

Bernard -- 18 at the time of the crime -- was not the gunman and Montgomery -- the first woman killed by the federal government in nearly 70 years -- suffered severe mental illness that stemmed from a history of abuse, their attorneys separately argued.

"Because we cannot ensure we get death penalty cases right every time, Biden will work to pass legislation to eliminate the death penalty at the federal level, and incentivize states to follow the federal government's example. These individuals should instead serve life sentences without probation or parole," according to Biden's "Plan for Strengthening America's Commitment to Justice."

Led by Pressley and Illinois Rep. Dick Durbin, lawmakers have introduced legislation and cosigned letters to the Biden administration and Garland, expressing their imperative reasons why the death penalty on the federal and state level should end immediately.

Smith and Kwame Ajamu, who both work as motivational speakers for Witness to Innocence, a nonprofit organization that rehabilitates and empowers former death row survivors, cosigned a letter with over 80 other nationally recognized criminal justice and civil rights advocacy organizations. The letter was delivered to Biden urging him to abolish the death penalty. Witness to Innocence was founded by anti-death penalty advocate Sister Helen Prejean.

Since the six-month federal execution spree of 13 men and a woman ended on January 16, there haven't been any scheduled federal executions -- but state-sanctioned executions in Ohio and Texas are calendared into April 2024.

Racial disparities and wrongful convictions

Biden's reasoning for stopping the death penalty is also in part because of the number of men and women who have been exonerated after receiving a death sentence. Garland testified during his Senate confirmation hearing last month that the number of people in death penalty cases who were exonerated gave him "pause" on his views of the practice.

"The fact of the matter is that these death sentences are not about justice ... Like slavery and lynching did before it, the death penalty perpetuates cycles of trauma, violence, and state-sanctioned murder in Black and brown communities," according to January 22 letter to Biden that was cosigned on behalf of 35 members of Congress.

The White House has not commented on the death penalty since January 25 when Press Secretary Jen Pskai said Biden is "opposed" to the practice. To end the federal death penalty, legal advocates like Miriam Krinsky with Fair and Just Prosecution have said Biden can end it with a stroke of a pen at any time.

"The president has the unilateral, Constitutional power to change the sentences of every man and woman on federal death row to life sentences. He could do this in a matter of minutes, with a few strokes of his pen," Krinsky told CNN in a previous interview.

The White House did not provide an update on Biden's death penalty pledge. The Justice Department deferred to Garland's responses from his confirmation hearing.

Wrongful convictions and wrongful convictions connected to the death penalty have stark racial disparities when you consider that Black and Latino people make up 13.4% and 18.5% of the US population, respectively, according to the US Census Bureau.

"My very first argument against capital punishment is the fairness of it. When you cannot make something as atrocious as taking a human life for a crime against humanity and society, fair, you should not do it," Ajamu, who is the chairman of the board for Witness to Innocence, said.

Ajamu has questioned why the justice system, in Ohio at least, has sought the death penalty for more people of color than White people. The three years while Ajamu was on death row, the demographics there he said reflected his peers more than the makeup of the jurors who wrongfully convicted him.

Ohio has executed 56 people since 1976. Currently, Ohio has 141 people on death row that include 79 Blacks, 56 Whites, four Latinos and one Asian, according to the DPIC. The state is 81% White, 13.1% Black, 4% Hispanic and 2.5% Asian, according to the US Census Bureau.

Nationwide, as of October, there are over 2,500 men and women sitting on death row that consist of 1,062 Black people, 1,076 White people, 343 Latinos, 24 Native Americans, 47 Asians and one identified as other. Of the 49 men currently on federal death row there are 20 Blacks, 21 Whites, seven Latinos and one Asian. Since the summer, state executions were postponed in part due to the coronavirus pandemic. Those that were on the docket prior to Biden's inauguration, so far, have not gone forward.

Despite all the calls to end the death penalty, US Attorney Offices across the country have still submitted notices of intent to seek the death penalty for defendants.

As recent as February 25, the acting US Attorney Michael Bennett for the Western District of Kentucky submitted an application to seek the death penalty for Victor Everette Silvers. Silvers is charged in the 2018 killing of his estranged wife and Fort Hood Soldier Brittney Niecol Silvers. The request was authorized by former acting Attorney General Jeffrey Rosen.

Barr gave authorization to the Eastern District of New York in November to seek the death penalty for MS-13 gang member Jairo Saenz, who was convicted for the murders of seven people.

"Don't get me wrong, I'm not saying people shouldn't be punished for the things that they do. What I'm saying is, we as humans don't have the right to say who lives and dies, I mean that don't make sense to me," Smith said. "It doesn't deter crime and it is expensive. What we need to do with the money used for all these people that sit on death row how many years, we need to put it in to homelessness, we need to put it in mental health, we need to put it in education, roads, bridges, all this kind of stuff."

Capital punishment is the 'worst thing...'

"Death row is mental anguish times 10,000. There's no greater fear than waiting to die," Ajamu said.

Ajamu, who was born Ronnie Bridgeman, was 17 when he went from a juvenile facility to death row with dozens of other adult men including his brother Wiley and their friend Ricky Jackson who were sentenced to die before him. They were separately convicted and sentenced to die for the 1975 murder of Harold Franks in Cincinnati, Ohio.

"I stepped into that bitty cell where I can stretch my arms out and touch each wall, the toilet was in the back and there were two dials on the radio -- Country and Western," Ajamu said.

Ajamu, now 63, said he was shocked that he was sentenced to die a month before his 18th birthday.

"It didn't resonate with me until a sheriff, who was about my age now, took me to the bullpen and I heard the tenderness, the compassion in his voice when he escorted me back to the jail, he said 'C'mon, I gotta do this,'" Ajamu told CNN.

His first day on death row he got in trouble for keeping the lights on in his cell after 11 p.m. and by the third day, he wanted to "squeeze through the cell and run away" after listening to another inmate scream "oh, lord no" for six hours straight. "The rest of death row was carrying on with their day as the man was screaming," he said.

Ajamu, Bridgeman and Jackson spent three years on death row until the US Supreme Court ruled in 1978 that the law was unconstitutional, and all of their sentences were commuted to life. The death penalty law reinstated in 1981 and Ohio went on to execute 56 people, to date. It wasn't until 2005 that it was ruled unconstitutional to issue the death penalty for someone who was under the age of 18 at the time of the crime.

Ajamu said he used his 27 years behind bars to convert to Islam, get his education, become an education administrative clerk where he encouraged other inmates to get their education and oversaw 5,000 graduations.

While Ajamu was fighting for his freedom, his mother, six aunts and his older sister each passed away. He said two months before he was released on parole in 2003, another brother died.

Ajamu said he has been repeatedly asked if he was angry at the 12-year-old boy who falsely claimed he saw the murder.

"Yes, he gave the Judas statement, but he was a wayward kid that had a hard time fitting in. We later learned that he when he got to the precinct, he wanted to change his mind and the police yelled at him and threatened to charge his mother, who was in the hospital with cancer, with perjury. He didn't have any parental guidance ... he was also victimized by the system," Ajamu said.

In 2003, Ajamu was released on parole and he fought another 11 years to get himself, his brother and Jackson fully exonerated. With assistance from new attorneys from the Ohio Innocence Project and recanted testimony from the sole eyewitness, 39 years later in November and December 2014, all three men were exonerated.

During Ajamu's three years on death row, he said he was "fortunate enough not to be there when someone was executed ... capital punishment is the worst thing we can do to each other as human beings."

'No one prepares you' on how to wait to die

Before Smith's 18th birthday, she was living on her own in Columbus, Mississippi, with her two young children. When her 9-month-old son, Walter, wasn't breathing on April 12, 1989, she sought help from her neighbors and was given instructions on how to do CPR -- for an adult.

"I never had CPR training before and I was just trying to get him to breathe, it was the worst thing that ever could have happened ... I was panicking and grief stricken," Smith told CNN.

Baby Walter died the next day and Butler was charged with his death. She was not allowed to go to his funeral.

When Smith went to trial in March 1990, she said she had only met her lawyer two days before. The prosecution's case was littered with inconsistent statements Smith allegedly made to police that concluded she abused her son, she recalled. No witnesses were produced on Smith's behalf and her requests to testify were ignored by her attorney.

A judge sentenced her to die.

"Hearing those gates close behind me and knowing that you'll never see outside again ... no one prepares you for that, you can't be prepared for that," Smith said. "They fingerprint you and they strip you of all your clothes and they just took everything from me, my dignity, they took everything from me."

Smith was sentenced on March 13, 1990 and her initial death date was set for July 2. When July 1 came, Smith said she tried to "sleep it away" like the next day wasn't really going to happen and that "someone would come and help me."

"I remember listening to all those keys and sounds. The echoes of the doors closing because I thought that it's like when you watch on TV that they'll come in with the ball and the chain and they take you down this long hallway. That's what I thought was going to happen," Smith said.

Smith said she hadn't heard from her attorneys and learned from another death row inmate that she wouldn't die the next day. She didn't.

During her time, she said she received letters from a friend who connected her to attorneys with the Southern Poverty Law Center and Reprieve.

Prior to Smith's nearly six years in prison, she wanted to serve in the Air Force and work in the criminal justice system. "Isn't that funny?" she said as she grimaced and shook her head in disagreement.

Once Smith was acquitted after trial in December 1995, she said the first thing she did was get trained in CPR. She is currently suing the state of Mississippi to get the manner of death on her son's death certificate amended from homicide to undetermined in order to fulfill complete exoneration.

"It still says to this day that he was murdered and that's just not true ... I mean if I want to go to school to be a nurse, where I can do that with something like that on my record," she said.