Cayley Mandadi and Taylor Clement, best friends since ninth grade, had a streak – Snapchatting every morning.
Taylor Clement: Every single day. … She was much more of a morning person. So I would get mine first thing in the morning.
But on Monday morning, Oct. 30, 2017, there was no word from Cayley.
Taylor Clement: I didn't get a Snapchat at 8 o'clock in the morning, like I usually do. … That's actually how I knew something was really wrong.
Both good students, they bonded in science class. Clement says she was instantly drawn to Cayley.
Taylor Clement: She had like, a really infectious smile and the big eyes and like, the loving heart.
The two separated to go to different colleges. That October morning, Cayley was on Clement's mind.
Taylor Clement: As I'm working in the library, it's in the back of my head, like, I haven't heard from her.
Clement didn't know it, but just hours earlier, Cayley's mother Alison Steele and stepfather Lawrence Baitland were awakened at 4 a.m. with horrifying news.
Lawrence Baitland: "Your daughter's been involved in some incident, and she has been life-flighted to Kyle, Texas."
They raced from their home in Houston to the hospital, praying Cayley was OK.
Peter Van Sant: What was it like when you entered that room? What did you see?
Alison Steele: I saw my daughter's body smashed.
Lawrence Baitland: I could see that she was on a ventilator … and my heart just stopped. And I knew that it was bad.
Within hours, Cayley's parents were told there was no hope for recovery. Their daughter, just 19 years old, once so full of life, was soon declared brain dead. Baitland and Steele want the world to know what happened to her.
Alison Steele: All that potential had been destroyed. And not knowing how it happened. Or how it was even possible.
They invited Cayley's friends to see her one last time. Clement sat with Steele as she held Cayley's hand and prayed.
Taylor Clement: I remember her repeating over and over, "this has to be for something, this has to be for something."
Cayley had previously requested that her organs be donated to help others. As she was taken to surgery for that procedure, her parents said goodbye.
Alison Steele: It was very emotional. … But, of course, we didn't want to let her go. But this is what had to be.
Just days before, things seemed to be going well for Cayley. A sophomore communications major at Trinity University in San Antonio, she had joined a sorority and was a cheerleader. And she'd met a boy.
Alison Steele: Cayley at the time was very much in love with the only serious boyfriend she had ever had. His name was Jett Birchum.
Birchum was a Trinity football player and fraternity brother. Cayley dated him freshman year, but they broke up.
Alison Steele: What she told me was, "I don't know that he wants a serious relationship." And she did.
Taylor Clement: I think that part of her life got very murky for her very fast.
There was another man in Cayley's life. Mark Howerton was 22 years old and had been a star high school baseball player
Howerton lived in Houston but was often on Trinity's campus visiting friends. That's where he met Cayley.
John Hunter: I think that they're both very beautiful people and I think that that was the primary attraction.
John Hunter is Howerton's lawyer.
John Hunter: I think that there were problems with her relationship with Jett. … And Mark was offering an alternative to that.
Both Jett and Mark knew Cayley was seeing the other man and neither, friends say, liked the competition. Then, just one month into this new relationship, Mark Howerton rushes Cayley to a small rural hospital in Luling, Texas.
While medical staff tended to Cayley, police officers interviewed Howerton in the quietest place they could find – the hospital chapel. It was recorded on the officer's bodycam.