Man who told Fort Worth jury woman’s death was accident is found guilty of murder
Furious that Donna Alexander, a woman whom he was dating, would not come to a Dallas bar to pick up him and a friend at the end of a night of drinking, Nathaniel Mitchell sent her a torrent of text messages.
After not responding to most of them, Alexander made it clear in a text that she would remain at her Grand Prairie house and that he was not welcome there.
“You won’t get the chance to kill me,” Alexander wrote on Sept. 21, 2018, at 12:06 a.m.
Alexander and Mitchell had argued hours earlier when she viewed on his cellphone material connected to other women. They had a physical confrontation in her car during an ongoing dispute about monogamy. Alexander wanted such an exclusive arrangement. Mitchell did not.
“I’m very sorry. I’ll never touch you again,” Mitchell wrote in a text as he continued to try to convince Alexander to retrieve him.
Mitchell eventually asked another woman to pick him up from the bar, she agreed and he arrived in early morning outside Alexander’s house intending only, he would say later, to get his clothes.
Alexander’s teenage son woke to Mitchell banging at the door and testified at Mitchell’s murder trial in a state district court in Tarrant County that, sometime later, he heard the sound of breaking glass.
Mitchell had gone to rear of the house, broke a window in the master bedroom and entered. The glass cut his skin and his blood was found on the blinds.
From the witness stand, Mitchell described an angry bathroom encounter.
At one point, Alexander referenced another woman whom Mitchell had recently dated.
“I should’ve stayed with Kathy,” Mitchell retorted.
At that, Alexander sprayed Mitchell in the face with an orange mist of mace, and he fell into the tub.
The spray rendered him unable to see, Mitchell testified.
A stool on wheels that typically was tucked under a vanity counter ran into Alexander, knocking her down, Mitchell testified, and she struck her head during her fall.
Mitchell said he peered through Alexander’s thick hair to try to view the injury, then carried her to a car and drove her to a microhospital, a Baylor Scott and White emergency center in Grand Prairie.
The stool was under the counter when a police officer entered the house to check the welfare of Alexander’s children, according to a video recording of the officer’s body-worn camera.
The jury was not persuaded by the accidental fall argument offered by the defense.
Jurors concluded that Mitchell committed felony murder by pushing or shoving Alexander with his hand or arm causing her to hit an unknown object, likely the bathroom floor, which caused Alexander’s death. The jury found he was in the course of the commission of burglary.
Murder as a knowing or intentional death or as a death resulting from an attempt to cause serious bodily injury were also verdict options, as was manslaughter, a reckless killing.
After a six-day trial at which visiting Judge David Hagerman presided, the jury in the 432nd District Court in Fort Worth on Monday convicted Mitchell of murder and determined that his punishment should be 45 years in prison.
The jury was instructed to consider a prison term of five to 99 years or life.
Tarrant County Assistant District Attorney Sarah Sherman told the jury that a term of at least 41 years, Mitchell’s current age, was appropriate and that the panel should consider working, “your way up from there.”
Defense attorney Jack Strickland argued that Mitchell merited a minimal sentence of perhaps five or 10 years. Strickland was, with attorney Steve Gebhardt, appointed to represent Mitchell.
Precisely how Alexander came to suffer the brain and skull injury that caused her death was at the core of the trial.
Experts reached a range of conclusions on whether the swelling and subdural hemorrhage inside her head were the result of an accidental fall, a forced fall or being struck by an object.
Press coverage at the time of Alexander’s death focused in part on her operation of Anger Room, a business in Dallas where customers could alleviate stress by smashing items in rooms made to look like a workplace or a living area.
Much like the cause of the head injury, whether Mitchell was living at Alexander’s house at the time he broke the window and indeed what constitutes living together, was in dispute at trial.
Mitchell drove her to the microhospital, staffed by one doctor per shift, where she moaned to a nurse and could not communicate what had happened. Mitchell told a nurse that Alexander slipped and fell outside the shower and hit the back of her head.
Before she died three days later on Sept. 24 at Baylor University Medical Center Dallas, Alexander was unable to speak or give police an account of in what way she was injured.
The nurse, two emergency medicine physicians and a forensic pathologist testified as state witnesses to offer opinions on in what way Alexander may have sustained the injury.
In the state’s opening statement, Assistant District Attorney Chase Payne told the jury that although the expert assessments were not definitive, evidence of the context of the couple’s time dating and Mitchell’s efforts to lie, manipulate and cover up would help to show the panel that Mitchell intentionally killed Alexander.
The nebulous elements of the injury were clear in the testimony of the doctor who treated Alexander at the microhospital.
“You don’t know what caused the injury?” Gebhardt asked on cross examination of Dr. Dillon Paul.
“That’s correct,” Dr. Paul testified.
The shower slip account to the nurse and a direct encounter he described in a text message to a childhood friend were among several ways that Mitchell recounted the cause of the injury.
“Me and Donna got into it,” Mitchell wrote in the message that the state displayed on a screen to the jury.
Alexander was “chasing me and fell and bumped her head,” he wrote.
The Mitchell case was originally filed as a capital murder under the state’s allegation that the death was a killing that occurred when Mitchell broke a window to get into Alexander’s house. A grand jury indicted Mitchell on murder.
Alexander grew up in Chicago and moved to the Dallas area as a young adult.
She first tested her Anger Room business model by selling to friends and relatives time to bash household items in her garage. Similar businesses were started nationwide after Alexander pioneered the idea.
Mitchell grew up in Gary, Indiana, worked in human resources and has nine children.
In its punishment case, the defense asked the jury to take into account in its determination Mitchell’s 10-year military service. He deployed three times during his time as a U.S Army medic.
During one of the deployments, to Iraq, he handled the body parts of dead soldiers and developed post traumatic stress disorder. Mitchell had a difficult transition to civilian life.
Other elements to consider in punishment, the defense argued, were Alexander’s obstinance in declining immediate access to Mitchell’s clothing and whether Alexander’s life may have been saved with a quicker transfer to a hospital with an intensive care unit. Alexander was at the microhospital for about two hours and 45 minutes.
“I’m not trying to blame her for her own death,” Strickland told the jury.
Alexander could have flung Mitchell’s clothing on the lawn, the defense attorney said.
“She didn’t have to mace him in the face,” Strickland said.
This story was originally published May 14, 2025 at 10:20 PM.
