Cayley Mandadi, 19, was a typical Texas teenager who lived his life through school, sports and boys. Friends say she had a big heart and was “full of love.” Her mother says Cayley was a happy person, confident, warm and always smiling.
Mandadi was a sophomore studying communications at Trinity University, a small liberal arts college in San Antonio, Texas. In the fall of 2017, friends say Mandadi finally felt like she fit in at school. She joined a sorority and was a member of Trinity’s cheerleading team.
Young love
Mandadi dated Trinity student and footballer Jett Birchum in her first year. But the relationship was on and off again.
A new man in Mandadi’s life
There was another man in Mandadi’s life: 22-year-old Mark Howerton. Growing up, Howerton was a star baseball player in high school. Howerton was not a student at Trinity, but often visited his friends on campus. That’s how he met Mandadi. In October 2017, their friendship turned into a romantic relationship.
A rocky relationship
The relationship between Howerton and Mandadi quickly became rocky. According to campus police, Howerton tore apart Mandadi’s dormitory a few weeks before her death. After an argument, Howerton reportedly threw her clothes into the trees, cracked a sliding glass door and later destroyed her laptop. Trinity University police were called to the scene and Howerton was banned from campus.
A weekend full of parties
The last weekend of October 2017, Mandadi and Howerton attended the Mala Luna Music Festival in San Antonio. The couple used MDMA, a drug known as Molly or ecstasy. This photo was taken at the music festival.
Tragedy strikes
According to Howerton, the couple left Mala Luna on Sunday, October 29, 2017, sometime after 4 p.m. They got into an argument after seeing Mandadi’s ex-boyfriend, Jett Birchum, at the festival.
Howerton said they continued to argue in the car, but eventually stopped in a parking lot to have “rough” make-up sex. Howerton later told police that Mandadi stopped breathing some time after sex. At one point he took her to the emergency room.
A disturbing scene
When Howerton arrived at the emergency room, Mandadi was sitting in the passenger seat of his car, nearly naked and unconscious. A paramedic testified that she saw “multiple bruises” on Mandadi’s legs and immediately began CPR.
Mark Howerton’s hands
As doctors tried to save Mandadi’s life, officers at the scene interviewed Mark Howerton about what happened that night. They took this photo of his hands,
Mark Howerton arrested
Three months after Mandadi’s death, her autopsy report was released. It found that she died of blunt force trauma to the face and head, and ruled her death a homicide. Several weeks later, Howerton was arrested and charged with murder and assault. He pleaded not guilty and was released on bail.
Defending Mark Howerton
In December 2019, Howerton was tried in San Antonio for Mandadi’s murder.
“This is a case where there is more than meets the eye and things are not what they seem,” John Hunter, Howerton’s attorney, told “48 Hours.”
Mandadi’s ex-boyfriend takes the stand
During the trial, Birchum told the jury what he saw at the Mala Luna Music Festival. He testified that he saw Howerton and Mandadi “having an intense conversation” and Mandadi “trying to create space” and “get away.” He said he then witnessed Howerton “extend his right arm, hook it around her shoulder and pull her closer.” And then turns and walks away.”
During cross-examination, Hunter questioned Birchum about what he said he saw that day. Birchum initially told police he saw Howerton pick up Mandadi and put her in his car as they left the festival. On the stand, Birchum admitted that he misled police about it and testified that he did not actually see Howerton put Mandadi in his car.
The defense theory
The defense presents a different theory about how Mandadi suffered her injuries that day. They claim Mandadi’s bruises were the result of the medical staff and not Howerton. They say the cause was due to the organ donation process. When medical professionals desperately tried to revive Mandadi seven times, they broke one of her ribs and injured her body.
A hung jury forces Mandadi’s parents to launch their own investigation
After ten hours of deliberation over two days, the jury informed the judge that they could not reach a decision. A mistrial was declared.
While prosecutors planned to retry Howerton, Cayley’s mother Alison Steele (pictured) and stepfather Lawrence Baitland decided the jury needed more information about what happened in Howerton’s car.
Mandadi’s parents develop their own theory
Steele and Baitland focused on an autopsy photo that showed a bruise in the shape of a small dot above Cayley’s right ear and another larger bruise above Cayley’s left ear.
Steele says they believe Cayley’s fatal injury occurred when Howerton “reached from his driver’s seat, struck her in the left ear and drove her head into the window and lock button of the car.”
Steele and Baitland went to a used car lot where Steele posed in a car like the Mercedes Howerton he drove the night Cayley was killed. This is one of many photos Baitland took of Steele posing in the car. He told “48 Hours” that he “photographed her head in different positions while … holding the autopsy images, trying to see if they matched the door and it was an almost perfect match.”
Mandadi’s stepfather develops a 3D model
Encouraged by the photos he took, Lawrence Baitland, a NASA engineer, constructed a 3D model of Mandadi’s head. He included photos of Cayley and the autopsy photo showing the dot above Cayley’s right ear.
“So this gave me the confidence to move on to the next step, which is to look for the killer’s car,” Baitland said.
Tracking down the alleged murderer’s car and making a reenactment video
Bailtland has tracked down Howerton’s Mercedes. He convinced the owner to sell him the car.
Baitland and Steele then hired a private investigator who produced a reenactment video of what they think happened in the car, featuring actors similar in size to Mandadi and Howerton. This is a still image from that video.
Howerton was found guilty of aggravated assault at his second trial
Howerton will be seen at the start of his second trial in May 2023.
The prosecution decided not to enter Steele and Baitland’s reenactment video into evidence, fearing that the defense’s cross-examination about it could undermine the case.
The jury found Howerton not guilty of murder, but rather of aggravated assault causing serious bodily harm. He was sentenced to the maximum prison term of twenty years. He will be eligible for parole in May 2033
Mandadi’s parents continue to fight for the victims
Alison Steele turned her grief into action. In September 2019, she succeeded in getting the CLEAR Alert Bill passed. When someone between the ages of 18 and 64 goes missing in the state of Texas, an emergency message is sent to the community. Steele wants “Cayley’s story to be used to help other people.”
Friends forever
Taylor Clement will never forget her best friend. She told “48 Hours” that she had always planned to one day have Mandadi as a bridesmaid at her wedding, and as godmother to her future children. She said this photo is of them “smiling at prom [her] absolute favorite.”
