‘Twisted Love:’ The Cayley Mandadi tragedy

Texas Crime Stories follows the trials of the boyfriend of Cayley Mandadi, Mark Howerton.

Cayley Mandadi seemed to have it all — college cheerleader at Trinity University, sorority member, smart and popular.

However, in September 2017, things changed for Cayley when she broke up with her boyfriend Jett Birchum.

The two had been together for about nine months when they broke up.

Not long after, Cayley started dating Mark Howerton.

No fairy tale

Mark was not a student at Trinity University but had a friend who went to the school and often hung out with the same crowds as Cayley.

As the two started to date, her friends weren’t too fond of Mark and noticed some unusual behavior.

Cayley started telling her closest friends that she wasn’t happy with Mark and wanted to break up with him, but she was afraid to.

Her friends noticed tension starting to escalate between the two.

In one instance, Cayley went to a party that Mark didn’t want her to go to and he trashed her dorm room and threw her clothes out the window.

When Trinity University police got a noise complaint, Mark was found inside alone and he said he was waiting for Cayley to return.

Due to the fact he wasn’t a student and police noticed the damage to the room, he was told to leave. Charges were later filed and Mark wasn’t allowed on campus.

Cayley continued to see Mark and tried to break it off, but he would tell her he was going to commit suicide if she left him.

As things progressed, they didn’t get any better and Cayley started reaching out to her ex, Jett. She told him that she was scared.

October 29, 2017

In the fall, Cayley went with Mark to the Mala Luna Music Festival at Nelson Wolff Stadium.

The couple weren’t there long, Cayley and Mark spotted her ex there and decided to leave.

That was around 3:45 p.m.

Cayley wasn’t seen again until around 10:30 p.m. when Howerton showed up at a Luling hospital.

She was unconscious, nude from the waist down, and covered in bruises.

CPR was started right away but it was too late, Cayley was brain dead.

On October 31, she was taken off life support and later died.

The investigation

Mark was immediately questioned at the hospital by police, the story he told didn’t add up.

He told police they left the festival and were going to drive back to Houston because she no longer wanted to go to school and wanted to get away from her friends and family.

He said they argued about seeing her ex but eventually pulled over off I-10 at a Valero to have what Mark says was rough makeup sex.

Mark also said the two had been drinking and had taken a large amount of the drug molly, or ecstasy.

After having sex, he said they got back on the highway but then he noticed Cayley had passed out and stopped breathing.

He said he panicked and took the exit for a hospital.

Police questioned him and asked what Valero he was referring to because they didn’t know of one in the area off I-10.

The Texas Rangers would soon get involved and help with the investigation.

Cayley’s autopsy report later ruled she had died of blunt force trauma to the head and that her death was a homicide.

Months after her death, a warrant was out for Mark’s arrest.

He was charged with murder and aggravated sexual assault.

The first trial

In December 2019, Mark stood in a Bexar County courtroom and what was revealed shocked many.

Prosecutors showed evidence of a possessive and controlling Mark who could easily lose his temper and try to manipulate Cayley.

Meanwhile, the defense painted a different picture. They stated the bruising on Cayley could have been caused by medical personnel as CPR was administered and that the drug she was on could have contributed to her death as well.

When Jett, her ex, took the stand, he got caught up in lies. His testimony didn’t match previous statements he made.

Jett testified that he saw Mark force Cayley to leave the festival by grabbing her forcefully by the arm but he later said that he actually didn’t see that and he just saw them walk away.

His testimony was damaging to the prosecutors.

In the end, during deliberations, the jury was deadlocked eight to four, ending in a mistrial.

The retrial

During the retrial in June 2023, cell phone evidence was shown for Cayley and Mark’s phones.

    • 2:37 pm - Howerton’s phone was at Trinity University
    • 3:42 pm - Howerton’s phone was near the area of Wolff Stadium where the Mala Luna Festival was taking place
    • 4:05 pm - Howerton’s phone was in the area off Highway 281 by the corporate Whataburger offices across from the Quarry
    • 4:23 pm - Mandadi’s phone starts showing up in the same area off Highway 281
    • 5:33 pm - Mandadi’s phone is still showing up at the corporate Whataburger offices
    • 7:14 pm - Mandadi’s phone is now in the area off Loop 410 near San Antonio International Airport
    • 7:27 pm - Howerton’s phone is now in the same area near the airport
    • 10:39 pm - Howerton’s phone is now in the area of Interstate 10 near Luling
    • These locations would dispute Howerton’s first version of what happened after leaving the music festival. He had told police the two stopped at a Valero off I-10 to have sex before proceeding to Houston.
    • The cellphone data would also show that Howerton drove around for a while before showing up at the Luling hospital.

After testimony and evidence were presented, the jury went to deliberate.

This time around they could consider the lesser charge of aggravated assault causing serious bodily injury.

In the end, they would find Mark not guilty of murder, but guilty of that aggravated assault charge, which is a second-degree felony.

He was later sentenced by 144th Dist. Court Judge Michael Mery to the maximum for that charge, which is 20 years in prison.

Prosecutor David Lunan said Cayley’s family was relieved to finally have some closure in her case.

“We’re happy, the family is satisfied that there is closure here. In having to meet with family members and friends and everything else who were affected by these crimes, and they’ve been hurting, and we are happy to conclude it today,” Lunan said.

Howerton is now serving his time at the Garza West Unity in Beeville, Texas. His parole eligibility date is in May 2033.

Cayley’s Legacy

Cayley’s mother, Allison Steele created the Cayley’s Calling organization and through that had legislation passed creating the CLEAR Alert.

The night Cayley died, several of her friends went in person to the local police department and begged for assistance in finding her. However, without an adult alert mechanism to enable a rapid response, law enforcement agencies were limited in what they could do.

On May 25, 2019, Governor Greg Abbott signed House Bill 1769.

According the Cayley’s Calling website, “Texas has now become the first large-population state in America to enact an adult kidnapping interdiction mechanism as strong as what the CLEAR Alert represents, and to provide a rescue mechanism for adults whose lives are endangered in other situations as well.”

The acronym “CLEAR” stands for Coordinated Law Enforcement Adult Rescue. Informally, the letters reflect the first letter of the names of victims of violence: Cayley Mandadi, D’Lisa Kelley, Erin Castro, Ashanti Billie, and the Rest (the other unnamed adults whose lives might have been saved if the CLEAR Alert had existed at the time of their deaths).

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About the Authors

Erica Hernandez is an Emmy award-winning journalist with 15 years of experience in the broadcast news business. Erica has covered a wide array of stories all over Central and South Texas. She's currently the court reporter and cohost of the podcast Texas Crime Stories.

Leigh Waldman is an investigative reporter at KSAT 12. She joined the station in 2021. Leigh comes to San Antonio from the Midwest after spending time at a station in Omaha, NE. After two winters there, she knew it was time to come home to Texas. When Leigh is not at work, she enjoys eating, playing with her dogs and spending time with family.

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