A Texas woman with a history of unpredictable behavior at work was taken into custody last month for allegedly shooting her boss in the head following a work-related dispute, and subsequently striking him with the tractor-trailer she was operating.

Patricia Ruth Holt, 57, reportedly had ongoing issues with Carl Joseph Donaldson, the 47-year-old manager of the trucking yard where she was employed, leading up to the fatal incident on July 24, according to the Daily Freeman.

Police reports indicated that Holt confessed to the arresting officers about her long-standing plan to kill Donaldson, citing that she’d been “fed up” with being “messed with” for an extended period. She claimed she hadn’t received any salary in the past two years, despite having commenced employment at Hutchins Trucking Yard the previous June.

Authorities stated that Holt issued threats to shoot others at the scene who were recording the incident before engaging them in a slow-speed chase. Police eventually used spike strips to immobilize her vehicle, after which she barricaded herself inside the truck’s cab for nearly four hours.

After her arrest, she told police she considered turning the gun on her self or attempting “suicide by cop.”

Tonya Donaldson, the wife of the deceased, told the Daily Freeman that Holt had been a difficult employee since her hiring, having previously faced disciplinary action for speeding.

“She immediately became defensive, which was our first indication that issues would arise every time we needed to address her conduct or provide coaching,” she said.

Holt also screamed and cursed at her husband for a reminder about the rules of the road.

“It was just normal stuff,” Tonya Donaldson said. “He would do it all the time.”

She told the paper she was at the yard when the shooting took place. Holt had gotten into an argument with a customer in Waco, and Donaldson told her to either apologize to the customer and pick up the load or empty the truck and leave it in Waco. But she drove back to the yard in Tyler, where she began driving the truck — aggressively — in circles.

“She was focused on Carl, her target was Carl,” Donaldson said. “She tried to hit Carl twice.”

Carl Donaldson climbed on running board to open the driver’s door, she said, but it was locked.

“At that time, I had my back turned and I heard a pop,” Donaldson said. “I turned around and looked and I see my husband flying through the air and falling on the ground.”

Holt accelerated and hit Carl Donaldson as he lay on the ground, she said.

In the wake of the shooting, Holt’s previous arrest — at her high school in New York in 1986 — was uncovered. In that incident, she was angry because an English teacher had removed her from class because of “behavioral problems,” the Daily Freeman said. After a meeting with the school district’s director of special services, Holt , then 18, went home, grabbed a gun, and came back to the school, looking for the teacher.

The teacher wasn’t in the classroom, so Holt went to the faculty lounge where two other teachers took her down and wrestled the gun away until police arrived.

She was initially charged with attempted murder, attempted assault, criminal trespass, and possession of a weapon. She pleaded guilty to attempted assault and was sentenced to five years probation. She was also ordered to undergo inpatient psychiatric treatment.

Holt has been charged with first degree murder in Donaldson’s death and is being held on a $1 million bond.