This story was originally broadcast on January 20, 2024.
When Cayley Mandadi, a 19-year-old sophomore at Trinity University, was brought to a Texas hospital on October 29, 2017, she was found nearly naked, bruised, and unresponsive. Her on-and-off boyfriend, Mark Howerton, informed doctors that they had consumed ecstasy at a music festival and she had passed out after consensual intercourse in his car. Tragically, Cayley passed away at the hospital.
In February 2018, Howerton was charged with Mandadi’s murder, with authorities claiming that the cause of death was blunt force trauma to the head. Despite this, Howerton’s trial ended in a mistrial a year later.
Cayley Mandadi, a sophomore studying communications at Trinity University in San Antonio, Texas, was described by friends as having a kind heart and being „full of love.“ Her mother stated that Cayley was a cheerful person who was trusting, warm, and always had a smile on her face.
Taylor Clement
A new trial was scheduled for 2023, as Mandadi’s mother Alison Steele and stepfather Lawrence Baitland believed that jurors needed more details about the events that occurred inside Howerton’s car. Steele, a scientist, and Baitland, a NASA engineer, initiated their own investigation into the matter.
„I needed to show the jury what happened to Cayley,“ Baitland shared with „48 Hours“ correspondent Peter Van Sant.
By utilizing autopsy images and consulting with experts, they formulated a hypothesis.
Could the couple’s investigation alter the outcome of the second trial?
CAYLEY MANDADI’S FINAL HOURS
Cayley Mandadi and Taylor Clement, best friends since ninth grade, had a tradition of sending each other Snapchats every morning.
Taylor Clement: Every single day… She was more of a morning person, so I would receive hers first thing in the morning.
However, on the morning of October 30, 2017, there was no message from Cayley.
Taylor Clement: I didn’t receive a Snapchat at 8 o’clock in the morning, like usual… That’s when I realized something was very wrong.
Both excellent students who bonded in science class, Clement was immediately drawn to Cayley.
Taylor Clement: She had a contagious smile, big eyes, and a loving heart.
Separated by different colleges, Cayley was on Clement’s mind that October morning.
Taylor Clement: While I was in the library, the thought that I hadn’t heard from her lingered in my mind.
Unbeknownst to Clement, just hours earlier, Cayley’s parents were informed at 4 a.m. of a terrible incident involving their daughter.
Lawrence Baitland: „Your daughter has been involved in an incident and has been airlifted to Kyle, Texas.“
They hurried from their Houston home to the hospital, hoping for Cayley’s recovery.
Peter Van Sant: What did you see when you entered that room?
Alison Steele: I saw my daughter’s body in a terrible state.
Lawrence Baitland: I could see she was on life support… And my heart sank. I knew things were bad.
Shortly after, Cayley’s parents were informed that there was no hope of recovery. Their daughter, only 19 years old and full of life, was declared brain dead. Baitland and Steele were determined to uncover the truth about what happened to her.
Alison Steele: All her potential was lost, and not knowing how it happened was devastating.
They invited Cayley’s friends to bid her a final farewell. Clement sat with Steele as she held Cayley’s hand and prayed.
Taylor Clement: I recall her repeating, „This must mean something, this must mean something.“
Prior to this tragic event, everything seemed to be going well for Cayley. A sophomore communications major at Trinity University in San Antonio, she had joined a sorority, was a cheerleader, and had recently met a boy.
Alison Steele: At that time, Cayley was deeply in love with Jett Birchum, her first serious boyfriend.
Birchum, a Trinity football player and fraternity member, had dated Cayley during her freshman year, but they eventually split up.
Alison Steele: She told me, „I’m not sure if he wants a serious relationship,“ while she did.
Taylor Clement: That part of her life became very complicated very quickly.
Another man in Cayley’s life was Mark Howerton, a 22-year-old former high school baseball star.
Howerton, who resided in Houston but frequently visited Trinity’s campus, crossed paths with Cayley there.
John Hunter: I believe they were both attractive individuals, and that was a primary draw.
John Hunter represented Howerton as his lawyer.
John Hunter: I think there were issues in her relationship with Jett… And Mark seemed like an alternative to that.
Both Jett and Mark were aware of Cayley’s involvement with the other man, and neither, according to friends, appreciated the competition. Then, after just one month into this new relationship, Mark Howerton hurried Cayley to a small hospital in Luling, Texas.
While medical personnel attended to Cayley, police officers questioned Howerton in the hospital chapel, the quietest spot they could locate. The exchange was recorded on the officer’s body camera.
DEPUTY CALENTINE (to Howerton/bodycam video): So tell me, where were y’all at today?
Howerton narrated to the officers that he and Cayley had attended the Mala Luna Music Festival, consumed alcohol, and ingested MDMA, also known as Molly or ecstasy.
Christy Jack, a Fort Worth-based attorney, was asked by „48 Hours“ to review the case files.
The situation escalated at the music festival, with Christy Jack revealing that an argument broke out between Jett Birchum and Howerton. Despite leaving in his Mercedes, Howerton and Cayley continued to argue as she admitted her feelings for Jett. Howerton expressed frustration in a police interview, urging Cayley to move on from Jett and criticizing her friends. He later mentioned having consensual rough sex with Cayley, during which he choked her but claimed it was not harmful. Cayley eventually stopped breathing, leading Howerton to attempt resuscitation before seeking medical help. The medical examiner later determined Cayley’s death was caused by blunt force trauma, leading to Howerton being charged with murder. As the trial unfolds, conflicting accounts of the events that transpired that night emerge, with the defense arguing against the prosecution’s claims of assault. Ultimately, the case hangs on the interpretation of Cayley’s injuries, with Hunter suggesting they were not indicative of foul play. John Hunter described the condition of Cayley Mandadi after the sexual assault nurse took photographs of her, mentioning that she had been resuscitated multiple times, had a chest tube inserted, and IVs placed in both arms. He also noted that she had been treated in a traumatic manner at the Luling hospital. Meanwhile, as doctors fought to save Cayley’s life, police interviewed and photographed Mark Howerton, with Officer Chris Adams noting redness on Howerton’s hands. Evidence suggested that Howerton had hit Cayley, and his muscular appearance led some to believe he used steroids. Despite initially cooperating with investigators, Howerton showed more concern for Cayley’s well-being than for himself. The autopsy performed by Dr. Suzanna Dana indicated that Cayley had been beaten to death, but some injuries may have been caused by medical care. The trial would also delve into Cayley’s troubled relationship with Howerton, with friends testifying about their stormy history and disturbing incidents leading up to her death. Jett Birchum, who was also present at the festival, observed Mark and Cayley moving towards the exit, seemingly against Cayley’s wishes. During the trial, Cayley’s ex-boyfriend, Jett Birchum, testified about what he saw at the Mala Luna Music Festival. He stated that he witnessed Howerton and Cayley engaged in an intense conversation, with Cayley trying to create space and distance herself. Birchum described Howerton reaching out his right arm, hooking it around Cayley’s shoulder, pulling her in closer, and then walking away. This testimony was deemed important by the court, as it indicated that Cayley may have been taken somewhere against her will.
However, during cross-examination, defense attorney John Hunter challenged Birchum on inconsistencies in his statements to investigators and a grand jury. Birchum admitted to exaggerating details to police out of concern for Cayley’s safety. Hunter also questioned Birchum about a drug charge and his probation status at the time.
Despite Birchum repeatedly invoking the Fifth Amendment during questioning, the damage to his credibility was already done. The defense also presented Dr. William Anderson, a forensic pathologist, as a key witness. Anderson argued that the bruising on Cayley’s body could have been caused by resuscitation efforts and the organ donation process, pointing to a possible skull fracture as evidence. This testimony aimed to cast doubt on the prosecution’s case against Mark Howerton.
After the defense rested, prosecutors brought in another medical examiner to challenge Dr. Anderson’s findings. The jury was left to decide whether Mark Howerton was responsible for Cayley’s death. The trial ended in a mistrial after the jury failed to reach a unanimous decision, with plans for a retrial in the future. This situation is completely ridiculous. While prosecutors are working to address the claims, defense attorney John Hunter has filed a motion to dismiss the entire case, citing Jett Birchum’s lies as part of the reason. Hunter argues that the use of false evidence by the prosecution undermines the entire judicial system.
A Texas couple, Alison Steele and Lawrence Baitland, investigated their teen daughter’s unusual death after sitting through the first trial. Steele, a scientist, and Baitland, a NASA engineer, worked tirelessly to gather evidence. They studied autopsy photos and recreated the scene in the car where their daughter was fatally injured.
Their efforts led to the discovery of crucial evidence, including a bruise on Cayley’s head that matched the car’s door. Baitland even created a 3D model of Cayley’s head to further demonstrate their theory. They eventually obtained the car in question and conducted a reconstruction to show how the fatal blow occurred.
The couple’s determination to seek justice for their daughter’s death is evident in their meticulous investigation and dedication to uncovering the truth. Their efforts have shed light on crucial evidence that could potentially change the course of the case. Perhaps a space alien came and left a little mark on her.
John Hunter: I almost feel like it’s not worth discussing because it’s so unscientific.
Years passed, and Alison worked diligently to pass the Texas Clear Alert Bill, allowing law enforcement to swiftly initiate searches for missing individuals aged 18 to 64. In 2021, a district court in Texas rejected John Hunter’s motion to dismiss the case, citing no evidence of prosecutorial misconduct regarding Jett Birchum’s testimony. Hunter appealed this decision.
Alison Steele: It was a dreadful experience, waiting anxiously without knowing what would transpire.
Hunter filed appeals up to the United States Supreme Court, which declined to hear the case.
John Hunter: We faced defeat in every court we pursued.
After more than five years following Cayley’s death, a second trial date was set for May 23, 2023.
Peter Van Sant: What is on the line here? Are emotions running high?
Christy Jack: The stakes couldn’t be higher.
JUSTICE FOR CAYLEY
In May 2023, Mark Howerton was about to face trial for the second time for Cayley Mandadi’s murder.
Taylor Clement: I felt confident that justice would prevail this time.
In the years since Cayley’s passing, Howerton was active on social media, displaying little remorse for his actions.
MARK HOWERTON (social video post): Wow. 75% of people think I’m guilty. That just means 75% of people in the world…can suck my d***.
Christy Jack: He was living lavishly and boasting about his legal victories against Texas.
Howerton’s attorneys, John Hunter and Hallie Pease, claimed his social media behavior was a coping mechanism for being wrongfully accused of murder.
Hallie Pease: He used social media to release tension.
During the first trial, jurors only considered one charge – felony murder. This time, more charges were added, including aggravated assault and criminally negligent homicide. The video made by Cayley’s parents was also brought into question.
Peter Van Sant: Did you want the jurors to see that video?
David Lunan: Initially, yes.
Presenting the video posed risks, including potential damage to the case during cross-examination.
Christy Jack: The judge allowed it, but the parents decided to withdraw the exhibit to retain their roles as witnesses.
The second trial commenced on May 23, without TV cameras. Alessandra Cranshaw’s opening argument remained consistent.
Alessandra Cranshaw: I told the jury to start where Cayley Mandadi’s life ended – in the car with the defendant.
However, a notable change occurred in the witness list – Jett Birchum was absent.
Christy Jack: There was nothing to gain.
Prosecutors introduced an expert on domestic violence, portraying Howerton as an abuser who manipulated Cayley, leading to her tragic demise.
This pattern was especially challenging for a 19-year-old Cayley to handle.
Christy Jack: She was unaware of the dangerous situation she was in.
John Hunter urged jurors to give Howerton the benefit of the doubt, emphasizing a pharmacologist’s testimony suggesting high levels of MDMA in Cayley’s system could have caused her brain bleed.
John Hunter: I always believed this was a significant factor in her death.
Prosecutors and Cayley’s family refuted Hunter’s claims, stating the dangers of MDMA were exaggerated.
Alison Steele: There is no documented case of MDMA causing a subdural hematoma.
Peter Van Sant: How do you respond to that?
John Hunter: Research on this topic is lacking.
Hunter planned to call the former medical examiner, Dr. William Anderson, whose previous testimony had damaged the prosecution in the first trial. However, prosecutors were prepared with a new witness to counter Anderson’s claims.
Alessandra Cranshaw: We were ready to refute all his claims from the first trial.
John Hunter: I didn’t want to engage in another debate about the skull fracture.
Thus, the defense rested without Anderson’s testimony.
Lawrence Baitland: It was shocking. There was a gasp in the courtroom.
A second panel of 12 individuals would determine Howerton’s fate, causing anxiety for Cayley’s parents and John Hunter after years of defending Howerton.
Peter Van Sant: What was the jury’s verdict?
John Hunter: The most beautiful words in English – not guilty.
Peter Van Sant: Not guilty of murder.
Alison Steele: My heart sank upon hearing the murder acquittal.
Christy Jack: They feared Howerton would walk free.
At the second trial, Mark Howerton was convicted of aggravated assault causing serious bodily injury and sentenced to 20 years in prison.
Additionally, Howerton was found guilty of aggravated assault causing serious bodily injury.
David Lunan: Relief and hugs were shared as Mark Howerton was taken into custody.
Alison Steele: Eight sheriff officers assembled to escort him to jail, bringing closure to a long and painful journey.
Also, das war ihre Art zu sagen, „wir sind für dich da.“ (weint) Also, das war eine – das war ein schöner Moment, das zu sehen.
Howerton wurde zu dem Maximum verurteilt – 20 Jahre Gefängnis. Für Cayleys Familie ist das bei weitem nicht genug.
Lawrence Baitland: Mark Howerton ist ein Monster, und er tut, was ein Monster tut.
Für Cayleys Freund Taylor Clement bleibt die Wunde roh.
Taylor Clement: Ich vermisse meine beste Freundin.
Baitland und Steele sagen, sie bereuen es nicht, Zeit und Geld für ein Video ausgegeben zu haben, das die Jury nie zu sehen bekam.
Lawrence Baitland: Es hat uns geholfen zu verstehen, was passiert ist. … Wir würden es wieder tun, wenn wir müssten.
„48 Stunden“ zeigte Steele dieses Video zum allerersten Mal.
Alison Steele: Es ist schwer zu sehen, weil das wahrscheinlich der Schlag war, der sie getötet hat.
Cayley Mandadi, in der Mitte, mit ihrem Stiefvater Lawrence Baitland und ihrer Mutter Alison Steele
Alison Steele
Cayleys Mutter, die betete, dass etwas Gutes aus dem Tod ihrer Tochter kommen würde, setzt ihren Kampf fort, anderen Opfern von Gewalt zu helfen.
Alison Steele: Was ich möchte, ist, dass ihr Opfer … anderen Menschen hilft. Das ist es, was sie wollen würde. Daran habe ich absolut keinen Zweifel.
Mark Howerton wird 2033 für Bewährung in Frage kommen.
„48 STUNDEN“ POST MORTEM PODCAST
Peter Van Sant und „48 Stunden“-Produzent Chris Ritzen diskutieren, wie sie diesen Fall über fünf Jahre, zwei Prozesse und die unkonventionelle Untersuchung, die Cayleys Eltern unternommen haben, um die Wahrheit darüber herauszufinden, was mit ihrer Tochter passiert ist, verfolgt haben.
Produziert von Mary Ann Rotondi und Chris Young Ritzen. Jenna Jackson und Ryan N. Smith sind Entwicklungsproduzenten. Mike McHugh ist der Produzent/Editor. Michael Loftus ist der Associate Producer. Gregory F. McLaughlin, George Baluzy und Michelle Harris sind Editoren. Peter Schweitzer ist der Senior Producer. Nancy Kramer ist die Executive Story Editor. Judy Tygard ist die Executive Producerin.