Brenda McLemore loved to draw animals as a little girl.

She married young and had a child.

But her life unraveled as the voices in her mind took over. Her family tried to get help. Twice put in mental hospitals, Brenda believed the voices when they told her she didn’t need any help for her schizophrenia. It left her family feeling helpless.

“You feel frustrated because the system sets them up to fail,” said Colleen Bradley, Brenda's sister who's 11 months older.

When Brenda died in July -- killed in a hit-and-run accident in Dallas -- she'd been on the streets for much of the last 15 years.

Her sister, Tammy McLemore, got the call from the Collin County Medical Examiner’s office three days after she died.

“It's been a nightmare,” Tammy said. “We wake up every day to a nightmare.”

The family is frustrated by the slow pace of the police investigation. They say repeated voicemails to the detective assigned to the case have gone unreturned.

Like so many of the department’s investigative units, the vehicle crimes unit is severely understaffed. It maintains some of the highest caseloads on the department. There are just four detectives currently investigating vehicle crimes. The unit once numbered more than 15 detectives.

They're assigned 10 or more cases every workday. The detectives investigated more than 150 traffic fatalities last year. Their overall caseload reached almost 18,000 cases last year.

Behind the realities of the police staffing situation is Brenda’s grieving family. To try to get answers, Brenda’s family hired a private investigator to jumpstart the stalled investigation.

Gil Wilson, a former Dallas police officer, says the video indicates the driver hit Brenda intentionally. “There's no doubt about it,” he said.

The hit-and-run accident happened at about 5 p.m. on July 2.

Wilson has viewed footage from all three cameras at the 7-11 at Preston and Belt Line roads. Brenda was well known to the businesses in that area and never gave anyone any trouble. She stayed mostly to herself.

“She didn’t even speak to the person who was driving the vehicle,” Wilson said.

The footage shows that the car drove into the parking lot from the adjacent shopping center. The driver pulls into one of the pumps and sits for about five minutes. The driver never gets out. Meanwhile, Brenda passes by the car and walks into the store for a cup of coffee.

After she walks by the car, the car pulls forward, bumps Brenda, slowly runs over her and drags her for about 67 feet.

Brenda, 53, died on the way to the hospital. She suffered 27 rib fractures, broken arms and her internal organs ruptured. Her pelvis was crushed.

“She was run over and dragged face down like she was a piece of garbage,” Tammy said.

The autopsy showed she had no alcohol or drugs in her system.

The family cherishes the last picture they have of Brenda – her face showing the toll of a life lived on the street.

They want people to remember the gentle soul who loved animals and once nursed an injured squirrel back to health.

“She was still Brenda underneath it all, the loving, caring sister we grew up with,” Colleen said.

The family always feared that Brenda would die alone. That she died that way breaks their hearts even more.

“Brenda Joy McLemore was a sister,” Colleen said. “She was a daughter, a mother. She had five grandchildren. She matters to us. She may not have mattered to them, but she was still a person.”

The sisters vow they will not rest until Brenda’s killer is found.

If you have any information about this case, you can Detective Nathan Williams in the Vehicle Crimes Unit at 214-671-0018. You can also call Crime Stoppers at 214-373-TIPS.