Amber McLaughlin set to become first openly transgender woman executed in the U.S.

Unless Missouri Governor Mike Parson grants clemency, Amber McLaughlin, 49, will become the first openly transgender woman executed in the U.S. She is scheduled to die by injection Tuesday for killing a former girlfriend in 2003.

McLaughlin's attorney, Larry Komp, said there are no court appeals pending. An online petition urging Parson to stop the execution has garnered nearly 4,900 of its requested 6,400 signatures as of Monday morning.

Attorneys submitted an application for executive clemency to the governor on Dec. 12, asking Parson to commute McLaughlin's sentence to life and noting that she was not given the death penalty in a trial by jury. When the jury deadlocked on punishment during her trial, a St. Louis county judge instead determined McLaughlin's sentence. As the application states, Missouri is one of only two U.S. states, along with Indiana, that allow trial judges to impose death penalty sentences in the event of a deadlocked jury.