HOUSTON – Mark Phillip Howerton, 22, is charged with murder, aggravated sexual assault and criminal mischief in the death of his girlfriend, 19-year-old Cayley Mandadi.
In October, Caldwell County authorities said Howerton took Mandadi to a Luling hospital, where she was unresponsive.
Howerton turned himself in to authorities in Bexar County on Wednesday.
"This is a terrible tragedy. It's a tragedy for Mark as much as it is anyone else. And the reality of this is Mark's innocent and he’s going to vindicate himself in court. And I ask that everyone who's watching this afford him the presumption of innocence that he's entitled to,” said John Hunter, Howerton’s attorney.
KPRC 2’s sister station, KSAT, in San Antonio reports Luling police were contacted to help emergency medical workers after they noticed Mandadi was brought to the hospital nude from the waist down and had bruises.
KSAT learned that investigators had questioned Howerton and told them he had known Mandadi for about eight months and had been dating her for a month.
Investigators said Howerton told them that he and Mandadi partied over the weekend, drank whiskey and took the party drug "Molly" on Oct. 28 and 29 while at a music festival in San Antonio. According to investigators, Howerton said the couple then argued over Mandadi’s ex-boyfriend and left.
After the festival Oct. 29, the couple again discussed the argument in their car, authorities said. Mandadi then agreed to go to Houston with Howerton.
Investigators said Howerton told them that the two stopped at a convenience store outside San Antonio to have sex in the car.
The arrest warrant said Howerton stated the sex was consensual and "rough." The warrant indicated Howerton admitted he knew Mandadi had bruises around her neck.
After that encounter, Mandadi said she wasn’t feeling well and passed out in the passenger seat without her clothes on, Howerton told investigators.
But authorities said Howerton continued to drive to Houston.
Just before getting to Luling, he said he noticed Mandadi stopped breathing and tried to do CPR before taking her to the hospital.
An autopsy showed the only parts of Mandadi’s body without injury were her back and the back of her leg. She was taken off of life support Oct. 30.
Howerton's bond is set at $225,000.