This story was originally broadcast on January 20, 2024. Cayley Mandadi, a 19-year-old sophomore at Trinity University, was taken to a Texas hospital on October 29, 2017. She was found nearly naked, bruised, and unresponsive. Her boyfriend at the time, Mark Howerton, claimed they had taken ecstasy at a music festival and she passed out after consensual sex in his car. Unfortunately, Cayley passed away at the hospital.
In February 2018, Howerton was charged with Mandadi’s murder, with authorities alleging that blunt force trauma to the head was the cause of death. Howerton’s trial ended in a hung jury a year later.
Cayley Mandadi, a sophomore studying communications at Trinity University in San Antonio, Texas, was described as a kind-hearted person by her friends and a happy and warm individual by her mother.
A new trial was scheduled for 2023, and Cayley’s mother and stepfather, Alison Steele and Lawrence Baitland, believed that more details about the events inside Howerton’s car were necessary for the jurors in the second trial. As a scientist and a NASA engineer, they conducted their own investigation.
Using autopsy photos and expert consultations, they developed a theory that could potentially impact the outcome of the second trial. The story delves into Cayley Mandadi’s final hours and the events leading up to her tragic passing, shedding light on the circumstances surrounding her death. Things escalated at the music festival when Christy Jack witnessed Jett Birchum and her friend arguing. Mark Howerton and Cayley got into a heated argument in his car after she revealed she still had feelings for Jett. Howerton tried to convince her to move on, but they ended up having rough, consensual sex. Cayley later stopped breathing, and Howerton attempted to resuscitate her before taking her to the hospital where she was pronounced dead. Despite initial beliefs of a drug overdose, an autopsy revealed Cayley died from blunt force trauma, leading to Howerton being charged with murder. The trial begins with conflicting testimonies and evidence, leaving the case open to interpretation. During the medical team’s efforts to save Cayley Mandadi’s life, Mark Howerton was interviewed and photographed by the police. Officer Chris Adams noticed redness on Howerton’s hands, potentially indicating his involvement in hitting Cayley. Despite initially cooperating with investigators, Howerton expressed more concern for Cayley than himself. The autopsy revealed that Cayley had been beaten to death, but some injuries were also attributed to medical care. The jury was about to learn more about Cayley’s troubled relationship with Howerton. Witnesses testified about the stormy history between Cayley and Howerton, including a disturbing incident before her death. Cayley’s friends recalled her final moments and the events leading up to her tragic death. Jett Birchum, who was also present at the festival, witnessed Mark and Cayley heading 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 described witnessing Howerton and Cayley engaged in an intense conversation, with Cayley attempting to create space and distance herself. Birchum stated that he then saw Howerton wrap his right arm around Cayley’s shoulder and pull her closer before walking away.
In court, Birchum admitted that he had initially misled investigators by exaggerating what he had seen. He explained that he was concerned for Cayley’s safety and wanted to ensure that the police searched for her. Birchum was questioned about inconsistencies in his testimony to a grand jury regarding the timeline of events at the music festival.
During cross-examination, Hunter challenged Birchum’s credibility, pointing out an unrelated drug charge that Birchum was on probation for at the time. Birchum invoked his Fifth Amendment right against self-incrimination multiple times during questioning. The defense attempted to undermine Birchum’s testimony by highlighting his past legal issues.
Dr. William Anderson, a forensic pathologist, testified for the defense, suggesting that Cayley’s injuries could have been caused by resuscitation efforts and the organ donation process. The defense argued that Cayley’s skull fracture could have been the result of a fall, rather than foul play.
After the defense rested, prosecutors brought the medical examiner back to challenge Dr. Anderson’s testimony, disputing his claims about Cayley’s injuries and the cause of her death. The jurors were left to decide whether Mark Howerton was responsible for Cayley’s death.
The trial ended in a mistrial after the jury could not reach a unanimous decision. The prosecutors planned to retry the case and prepare for a second round, focusing on challenging the defense’s medical expert witness. Despite the setback, both sides were determined to seek justice for Cayley Mandadi. In this situation, it is preposterous.
As the prosecutors tackle those allegations, defense attorney John Hunter files a motion to dismiss the entire case, citing Jett Birchum’s lies as part of the reason.
John Hunter: The deliberate use of false evidence by the prosecution undermines our trust in the legal system as a whole. … If this can happen, then there is no point in even conducting a trial.
Texas couple looks into their teenage daughter’s unusual death
19 photos
Alison Steele and Lawrence Baitland, Cayley’s mother and stepfather, attended the initial trial and concluded that jurors needed more information about what transpired inside Mark Howerton’s car.
Peter Van Sant: You decided to investigate?
Alison Steele: We did.
Lawrence Baitland: I felt it was necessary to show what happened in that car. … The jury needed to understand how it occurred.
She is a scientist, he is a NASA engineer. They got to work.
Lawrence Baitland: I spent countless hours studying autopsy photos, and I focused on one photo in particular that showed an impact on Cayley’s head, right in front of her ear.
The photo depicted a small dot above Cayley’s right ear. Other photos showed severe bruising above Cayley’s left ear, similar to what the medical examiner described in the initial trial.
ALESSANDRA CRANSHAW: And what do we see behind the ear?
DR. SUZANNA DANA: That’s a bruise. That’s a contusion.
Cayley’s parents believe that when viewed together, the photos tell a story.
Alison Steele: We believe that out of all the injuries, the fatal blow landed when he reached from his driver’s seat, struck her in the left ear, and drove her head into the window and onto the lock button of the car.
Indeed, in a recorded audio interview with the police on the day Cayley passed away, Howerton confessed to having done just that in the past.
RANGER RAYMOND BENOIST (police interview): Did you ever push Cayley’s head against the window?
MARK HOWERTON: I pushed her, and she hit the window once. That was over a week ago, yes.
Christy Jack: In many ways, it was like the same scenario repeated.
They needed evidence to persuade a jury. Cayley’s parents went to a used car lot, where Steele posed in a car similar to the Mercedes Howerton drove that fateful night.
Alison Steele posed in a car similar to the one Mark Howerton drove on the night Cayley died. Lawrence Baitland told “48 Hours” that he “photographed her head in different positions while… holding the autopsy images, trying to see if they match up with the door and it’s a near perfect match.”
Alison Steele
Lawrence Baitland: I photographed her head in different positions while I’m holding the autopsy images, trying to see if they match up with the door and it’s a near perfect match.
Baitland decided to take it a step further.
Lawrence Baitland: So, then I loaded this 3D modeling program.
Building a 3D model of Cayley’s head.
Lawrence Baitland’s 3D model of Cayley Mandadi’s head with the autopsy photo of the bruise above her ear layered in.
Lawrence Baitland
Lawrence Baitland: … the first thing you can do is you can create a solid out of that 3D mesh. And then… you can project an image onto it.
And this brought them closer to having concrete evidence.
Lawrence Baitland: This gave me the confidence to move to the next step, which was to track down the killer’s car.
Mark Howerton sold the car in 2018. Baitland located the new owner and purchased the car.
Peter Van Sant: What did you think of that?
David Lunan: Well, this is new. This is not something I’m accustomed to hearing in other cases.
Peter Van Sant: Show me what you believe happened.
Lawrence Baitland: Sure.
Peter Van Sant: Let’s go over to the passenger side…
The car in which Cayley sustained fatal injuries is parked in her parents’ driveway. Baitland stated that driving it home was a harrowing experience.
Lawrence Baitland: It’s agonizing. But she was showing us what happened, guiding us to this car.
Peter Van Sant (standing outside of the car): You believe that he struck her. When he did, she came over to this knob, her head hit it. Now you notice when you push it down, it doesn’t go flush.
Lawrence Baitland: Right. … This will not retract fully, no matter how hard you hit it.
Cayley’s parents opted to create a video to demonstrate their theory in court.
Christy Jack: They found two actors, a man and a woman, to dress the parts. They were similar in size and weight.
Lawrence Baitland: If we conducted the reconstruction ourselves, it would be considered biased and likely disregarded or discredited.
Thus, they enlisted a private investigator to produce the demonstration. They refrained from viewing it in case they were called to testify about it.
Texas couple attempts to solve their daughter’s mysterious death by
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The video is straightforward: showcasing three angles of what Cayley’s parents and their experts believe transpired.
Peter Van Sant: Could presenting a video like this to a jury potentially aid the prosecution’s case, if allowed?
Christy Jack: Jurors are very visual. … It makes the information more accessible to them.
Christy Jack: It illustrates how it could have occurred. And it addresses several of the questions that the jury had during the initial trial.
However, Hunter argues that regardless of how Cayley obtained that dot above her ear, it is all speculation.
John Hunter: It could be from something at the hospital, it could have been from something before she got into Mark’s car. … Could it be that it is from a locking mechanism on the door? I mean, possibly. “It is possible that a space alien came and marked her as well. John Hunter feels that the discussion is not worth it because it lacks scientific evidence. Years passed as Alison worked on passing the Texas Clear Alert Bill, which allows law enforcement to quickly search for missing individuals aged 18 to 64. In 2021, a Texas district court denied John Hunter’s motion to dismiss the case, stating there was no evidence of prosecutorial misconduct related to Jett Birchum’s testimony. Hunter appealed the ruling. Alison Steele described the waiting period as horrible. Despite filing appeals, Hunter lost in every court, leading to a second trial scheduled for May 23, 2023. Peter Van Sant questioned the high emotions involved in the case, to which Christy Jack emphasized the high stakes. The trial in May 2023 would see Mark Howerton facing charges for the murder of Cayley Mandadi for the second time. Howerton’s social media posts showed little remorse for his actions. His attorneys claimed that the posts were his way of coping with the pressure of being falsely accused. The second trial added more charges, and the video made by Cayley’s parents was considered for presentation. However, the risk involved led to the withdrawal of the exhibit. Prosecutors brought in an expert on domestic violence, highlighting Howerton’s abusive behavior towards Cayley. Hunter defended Howerton, claiming that the MDMA in Cayley’s system could have caused her brain bleed. The defense rested without calling a key witness, leading to a tense moment in the courtroom. Howerton was ultimately convicted of aggravated assault causing serious bodily injury and sentenced to 20 years in prison. The guilty verdict brought relief to Cayley’s family and ensured that justice was served.” Así que era su manera de decir, “estamos aquí para ti”. (llora) Así que fue un – fue un buen momento ver eso. Howerton fue condenado al máximo – 20 años de prisión. Para la familia de Cayley, no es ni mucho menos suficiente. Lawrence Baitland: Mark Howerton es un monstruo, y hace lo que un monstruo hace. Para la amiga de Cayley, Taylor Clement, la herida sigue siendo cruda. Taylor Clement: Echo de menos a mi mejor amiga. Baitland y Steele dicen que no tienen remordimientos por gastar tiempo y dinero en un video que el jurado nunca llegó a ver. Lawrence Baitland: Nos ayudó a aprender lo que pasó. … Lo volveríamos a hacer si fuera necesario. “48 Horas” le mostró a Steele ese video por primera vez. Alison Steele: Es difícil de ver porque probablemente fue el golpe que la mató. Cayley Mandadi, centro, con su padrastro Lawrence Baitland y su madre Alison Steele. Alison Steele. La mamá de Cayley, que rezaba para que algo bueno surgiera de la muerte de su hija, continúa luchando para ayudar a otras víctimas de violencia. Alison Steele: Lo que me gustaría es que su sacrificio … ayudara a otras personas. Eso es lo que ella querría. No tengo absolutamente ninguna duda al respecto. Mark Howerton será elegible para libertad condicional en 2033. “48 HORAS” POSTMORTEM PODCAST. Peter Van Sant y el productor de “48 Horas” Chris Ritzen discuten el seguimiento de este caso durante más de cinco años, dos juicios y la investigación no convencional que los padres de Cayley emprendieron para buscar la verdad sobre lo que le sucedió a su hija. Producido por Mary Ann Rotondi y Chris Young Ritzen. Jenna Jackson y Ryan N. Smith son los productores de desarrollo. Mike McHugh es el productor/editor. Michael Loftus es el productor asociado. Gregory F. McLaughlin, George Baluzy y Michelle Harris son editores. Peter Schweitzer es el productor senior. Nancy Kramer es la editora ejecutiva de historias. Judy Tygard es la productora ejecutiva. Más de CBS News. Peter Van Sant. Peter Van Sant es un corresponsal galardonado de “48 Horas, donde su reportaje sobre crímenes reales y justicia se presenta en múltiples emisiones y plataformas de CBS News. Durante una carrera que abarca casi cinco décadas, Van Sant ha cubierto muchos de los eventos más significativos de nuestra vida. Además, Van Sant presenta el podcast de mayor ranking “Blood is Thicker”.