Slain veterinarian Deidra Blackmon was the designated driver for two friends celebrating a bachelorette party on Saturday night.
Blackmon's friend, bride-to-be Samantha Mitchell, was with her that tragic night. She didn't want to go on camera, but told Dallas Television Station WFAA that Blackmon was an amazing friend.
"She was that one person that if you needed anything, she would do it," Mitchell said "She delivered every time."
Both women met when they were 8 years old on the playground of their elementary school. Mitchell was picking a scab and Blackmon told to her stop. When she didn't, Blackmon slapped her hand away.
Their friendship blossomed from there. They had sleepovers and made many memories throughout high school.
Mitchell's wedding is Friday. Blackmon was helping her plan the big day. She said so many are going to miss her.
"Every moment with her was incredible," Mitchell said.
According to an arrest affidavit, Mitchell got sick to her stomach on Saturday night, which led to a confrontation... which led to murder.
The celebration turned tragic in a flash.
There was a muzzle flash as Dr. Deidra Blackmon passed a car that had slowed in front of her on Bailey Boswell Road in Saginaw.
Alma Rodriguez, who Blackmon knows from high school, was sitting in the front passenger's seat, told police she saw and heard the gunshot. She called 911.
CALLER: "We're on Bailey Boswell. We've just been shot at! The driver has been shot in the head!"
OPERATOR: "I'm sorry. Do what now? Calm down."
Rodriguez was composed, despite the horror. Dr. Blackmon's car ran off the road into a pasture.
According to an arrest affidavit, Rodriguez pulled Blackmon's foot off the accelerator and gave the operator a description of the suspect's car.
The affidavit details a confrontation that happened moments earlier at a gas station. One of Blackmon's two passengers had vomited.
Her opened door blocked a woman from getting into the car in the adjoining spot. Dr. Blackmon apologized, and both cars left.
After the shooting a short time later, police released a surveillance photo of the mystery woman.
The affidavit said investigators received 11 tips, including multiple Facebook photos identifying Heather Thompson and suspected gunman Jeffrey Hansana.
Documents reveal that Saginaw police also got a lot of help from a Fort Worth police officer who had written down Hansana's license plate during a previous investigation. Investigators recovered a .45-caliber bullet.
Records show multiple drug and burglary arrests for Hansana.
Deidra Blackmon's colleagues recall a committed vet, devoted to the animals she cared for, and to their owners at the Animal Emergency Hospital of North Texas in Grapevine.
Dr. Bruce Nixon told News 8 that Blackmon loved saving animals' lives and when she couldn't, she would help families who lost a pet.
"This is what she wanted to do since she was 8 years old," Nixon said. "It was immensely rewarding for her."
Colleagues pinned black-and-red ribbons to their shirts this week, a visible reminder of Blackmon's heart and talent.
"The talent and the joy, the healing that this young lady gave to everyone she touched is just something that's irreplaceable," said Nixon.
Blackmon leaves behind her parents, a brother and boyfriend, Justin. Her funeral is Saturday.