By Andrea Lucia

ELLIS COUNTY, Texas (CBSDFW.COM) – Carla Hanson grows sunflowers because they were her daughter’s favorite flower.

She sleeps in her daughter’s bed at night with a quilt made from her old scrubs.

A sign in the bathroom warns visitors not to erase the scribbles her daughter last drew on the mirror.

Everywhere Carla goes she carries Heather with her.

“She had the biggest heart,” she said, touching the silver heart containing her daughter’s ashes that she wears around her neck.

Carla Hanson (CBS 11)

Heather Hanson was headed to work on January 29, 2019, when she slammed into the back of a pickup on I-45 in Ellis County.

Her death shocked the family.

“We were like what happened? How did this happen?” her mother recalls.

Heather Hanson

The Hansons started piecing together what little information they had about their daughter’s crash. To them it didn’t make sense.

Other drivers, they would learn, recalled seeing the truck Heather hit driving slowly.

“Real slow,” Joan Johnson told police.

“I had to slam my brakes,” said Dillon Pike.

The truck’s own computer showed it was traveling just 18 miles an hour in the fast lane.

“It shocked me, you know, and it threw me back in my seat,” said Tyrone Carr, who was driving the truck.

His blood tested positive in for a small amount of alcohol (.03 BAC) and a trace of methamphetamine.

It would be months before the Hansons would learn what police realized that morning.

Just hours before the crash, they’d pulled him over for speeding.

Carla said she assumed there would be video from body and dash cameras of both the traffic stop and the response to her daughter’s crash.

E-mails between the Hanson’s attorney and the city of Ferris show they were repeatedly told police couldn’t locate any body camera video.

“I didn’t give up!” said Carla.

She and her husband sued the city, citing in part its “failure to provide all documents requested.”

And, two years after the crash, she received the videos the city had claimed it didn’t have.

An officer, they show, discovered Carr going 92 mph in a 70 mph zone with a suspended license while on parole at 4:30 in the morning, just three hours before the deadly crash.

“I’m just trying to do everything I can for my kids,” Carr told the officer, explaining he was following his employer’s orders.

“Okay, I’ll tell you what man, I’m gonna work with you,” said the officer.

“They let him go. He shouldn’t have been on the roads,” said Carla.

A Ferris Police officer would later conclude Heather had been traveling at a “high rate of speed” and that the absence of skid marks meant she likely never applied the brakes.

The Ellis County District Attorney’s Office took the case to a grand jury, which determined there’s wasn’t evidence to file any charges against Carr.

Carla keeps combing through investigative records and videos from the scene, noting where police questioned whether Carr could be at fault and noting references to videos she says have yet to be released.

Supporting her are 2,300 followers on her Facebook page, Justice for Heather, where she posts regular updates.

“I’ve got an army behind me,” she said.

Carla says she’s determined to uncover and reveal the full story of her daughter’s death.

She wonders, at times, why she’s had to fight police to get it.

The Ferris Police Department said there’s no employee currently there able to discuss the case. Both the police chief and those involved in the case have since left the department.

The lead investigator, now working at a different department, told CBS 11 there were difficulties with Ferris’ video systems and they were prone to failure, potentially accounting for issues related to their release.