COLUMBIA, Mo. — The first openly transgender woman set to be executed in the U.S. is asking Missouri’s governor for mercy, citing mental health issues.

Lawyers for Amber McLaughlin, now 49, on Monday asked Republican Gov. Mike Parson to spare her.

McLaughlin was convicted of killing 45-year-old Beverly Guenther on Nov. 20, 2003. Guenther was raped and stabbed to death in St. Louis County.

There is no known case of an openly transgender inmate being executed in the U.S. before, according to the anti-execution Death Penalty Information Center.

“It’s wrong when anyone’s executed regardless, but I hope that this is a first that doesn’t occur,” federal public defender Larry Komp said. “Amber has shown great courage in embracing who she is as a transgender woman in spite of the potential for people reacting with hate, so I admire her display of courage.”

McLaughlin’s lawyers cited her traumatic childhood and mental health issues, which the jury never heard, in the clemency petition. A foster parent rubbed feces in her face when she was a toddler and her adoptive father tased her, according to the letter to Parson. She tried to kill herself multiple times, both as a child and as an adult.

Parson spokeswoman Kelli Jones said the Governor’s Office is reviewing her request for mercy.

“These are not decisions that the Governor takes lightly,” Jones said in an email.

Komp said McLaughlin’s lawyers are scheduled to meet with Parson on Tuesday.