It may have just been a matter of time. But quite a bit if it was.

Patricia Ruth Holt, 57, stands accused of one count of murder in the first degree, according to the Dallas County Sheriff’s Office.

In the charged incident, Carl Joseph Donaldson, 47, was shot in the head and killed in late July. The victim has since been identified as Holt’s then-manager at Hutchins Trucking Yard.

Nearly four decades earlier, Holt was charged with attempted murder.

On Sept. 25, 1986, when she was an 18-year-old high school senior living in Red Hook, a port-adjacent neighborhood in the borough of Brooklyn in New York City, the defendant came to school wielding a loaded 12-gauge shotgun, according to The Daily Freeman.

At the time, Holt was incensed about about being removed from an English class due to “behavioral problems” and appeared intent on striking down the teacher who had disciplined her.

The teacher was, thankfully, not in class at the time. So, Holt made her way to a faculty lounge – where she was promptly tackled by two other teachers, disarmed, and arrested without any injuries.

Initially charged with attempted murder, attempted assault, and criminal trespass – all felonies – and misdemeanor possession of a weapon, she eventually pleaded guilty to attempted assault and received five years probation due to her young age.

Over time, Holt moved to Florida. Then, North Carolina.

In June, the defendant began working for the North Texas-based trucking company in question. Roughly a month later, her boss would be dead.

The victim’s widow said Holt was trouble from the start.

During her first week on the job, Holt had to be told not to drive her big rig over the speed limit, the grieving woman told the Freeman. Then, the defendant had to be reminded about the rules of the road.

“She just went off,” the widow said. “He kept calm, but she just kept screaming that she’s been driving a f–ing truck for 30 years. She stormed out of the office, slammed the door and you could still hear her yelling and screaming outside. She just couldn’t stand being told what to do.”

The fatal flare-up began several hours earlier in Waco – a large city located just outside the northern edge of the Hill Country, a central-southern region of the Lone Star State. There, Holt allegedly got into an argument with a customer, the widow told the paper.

The alleged rage apparently carried several hundred miles north after the victim is said to have told Holt to apologize to the customer and pick up the load – or to to empty the truck and leave it in Waco.

The widow said Holt returned with the truck, but on arrival back in Hutchins – a small suburb of Dallas – the defendant allegedly got on a tractor-trailer, drove around in circles, then aimed to hit Donaldson.

The widow said her husband, a Purple Heart recipient, remained calm – and even jumped on the tractor-trailer to try and diffuse the situation and open the door. Then, came a tell-tale sound.

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

When law enforcement arrived on the scene, Holt allegedly led deputies on a slow-speed chase before spike strips were deployed. Then, she barricaded herself in the cab of the vehicle for just shy of four hours, according to the sheriff’s office.

She surrendered at 8:55 p.m., Central Standard Time, the sheriff’s office said in a press release obtained by The Dallas Morning News.

During an interview, the defendant allegedly said she hoped to kill herself or manage to end her life through “suicide by cop.”

Holt also allegedly told investigators she had her sights set on Donaldson “for months,” despite the length of her employment.

“[T]hey have been f—ing with her for too long,” a deputy wrote – allegedly transcribing the gripes uttered by the accused killer.

Holt is being detained in the Dallas County Jail on $1 million bail.