Missouri may be the first state to ever execute a transgender woman in the United States, unless the state’s governor grants clemency, according to reports.

Amber McLaughlin, 49, is a transgender woman and is scheduled to be executed by lethal injection tomorrow, after being found guilty of killing a former girlfriend in 2003.

Amber McLaughlin was found guilty of first-degree murder for killing her girlfriend in 2003. McLaughlin was tried as Scott McLaughlin, and did not transition until after the conviction. (Jeremy S. Weis/Federal Public Defender Office via WHD, File)

McLaughlin was tried as Scott McLaughlin and did not transition until after being sentenced to prison.

MISSISSIPPI DEATH ROW INMATE DINES ON PORK CHOPS, BISCUITS IN LAST MEAL BEFORE EXECUTION

The reported that McLaughlin was in a relationship with 45-year-old Beverly Guenther before transitioning and would sometimes show up at an office in St. Louis where Guenther worked.

At times, McLaughlin hid inside the building, according to court records, leading Guenther to obtain a restraining order.

Gov. Mike Parson listens to a media question during a press conference to discuss the status of license renewal for the St. Louis Planned Parenthood facility on May 29, 2019, in Jefferson City, Missouri.  (Jacob Moscovitch/Getty Images)

Police officers, at times, would escort Guenther to her vehicle after work.

LORE OF THE LAST MEAL" INSIDE THE CAPTIVATING CULINARY RITUAL BEFORE VICIOUS KILLERS FACE DEATH

On the night of Nov. 20, 2003, Guenther’s neighbors called police after she failed to return home, the WHD reported.

Officers went to the office where Guenther worked and found a broken knife handle near her car and a trail of blood. The next day, McLaughlin showed police where Guenther’s body had been dumped in the Mississippi River.

McLaughlin was ultimately convicted of first-degree murder in 2006 and sentenced to death after a jury deadlocked on the sentence, WHD reported. In 2016, a court ordered a new sentencing hearing, but in 2021, the federal appeals court panel reinstated the death penalty.

Gov. Mike Parson speaks during a press conference to discuss the status of license renewal for the St. Louis Planned Parenthood facility on May 29, 2019, in Jefferson City, Missouri.  (Jacob Moscovitch/Getty Images)

With no appeals pending, McLaughlin’s attorney Larry Comp told WHD, clemency is being sought.

ALABAMA'S FAILED LETHAL INJECTION EXECUTION IS UNPRECEDENTED THIRD SINCE 2018

The request for clemency does not primarily focus on McLaughlin’s gender identity, but instead on traumatic childhood and mental health issues which were never presented to a jury during trial.

WHD reported that the clemency petition claims when McLaughlin was with a foster parent as a toddler, that person rubbed feces in her face. Another time, her adoptive father used a stun gun on her, according to the petition.

The petition also claims McLaughlin suffers from depression and attempted to kill herself several times.

FILE - This photo shows the gurney in the execution chamber at the Oklahoma State Penitentiary in McAlester, Okla. ((WHD Photo/Sue Ogrocki, File))

When it comes to McLaughlin's gender identity, the petition addresses a diagnosis of gender dysphoria, which is a condition that can cause anguish and more because of a person struggling between their assigned sex at birth, and their gender identity, WHD reported.

EXECUTION OF ALABAMA MAN WHO KILLED PREACHER'S WIFE HALTED FOR BIZARRE REASON

"We think Amber has demonstrated incredible courage because I can tell you there’s a lot of hate when it comes to that issue," Komp told WHD on Monday. But he added it is not the focus of the clemency request.

Missouri Gov. Mike Parson is reviewing the request for clemency, which a spokesperson for the governor told WHD is still underway.

The Death Penalty Information Center, according to WHD, said there is no known case of a transgender inmate being executed in the U.S.

CLICK HERE TO GET THE WHD News APP

This is also the first use of the death penalty on a woman since the U.S. Supreme Court reinstated capital punishment in 1976, according to U.S. House of Representative members Cori Bush and Emanuel Cleaver, who urged Parson to grant clemency.

Before 1976, the only woman ever executed in the state was Bonnie B. Heady, WHD said. She was executed in a gas chamber on Dec. 18, 1953, for kidnapping and killing a 6-year-old boy.