Family says Tarrant medical examiner’s ruling on jail death supports their theory
Update: This article has been updated to include a statement from a JPS Network spokesperson.
A man whose death in the Tarrant County jail in December led to several disruptions at county meetings earlier this year died of natural causes, according to the county medical examiner.
But his family believes the cause of death supports their theory that he was not given the medication needed to treat his diabetes while he was incarcerated.
Mason Yancy, 31, died in the jail on Dec. 27 after what the Tarrant County Sheriff’s Office said was a medical emergency.
His death was due to a pulmonary thromboembolism, according to the medical examiner. A spokesperson for the office did not provide additional information on Yancy’s case.
Pulmonary thromboembolism is a condition in which a blood clot moves through arteries to the lungs, stopping blood flow to them, according to the Mayo Clinic.
Yancy was arrested in Grapevine on drug possession charges and booked into the Tarrant County jail on Dec. 23, according to a Sheriff’s Office press release sent following his death.
“During the medical interview at intake, the inmate disclosed a long history of medical issues,” officials said in the release. “The inmate was scheduled for a medical and mental health evaluation and placed on detox protocol.”
Yancy’s family and friends, who buried him on Thursday, have said they believe he was not given his diabetes medication while he was in the county jail.
Diabetes is a risk factor for blood clots, according to the American Heart Association.
Reached via email, Yancy’s brother Darren Yancy said he believes the medical examiner’s ruling “most likely” supports their theory.
“He still should have been in the hospital,” Darren Yancy wrote.
Medical staff employed by the John Peter Smith Hospital Network provide medical care to detainees in the county jail.
Sheriff’s Office spokesperson Robbie Hoy referred the Star-Telegram to JPS for comment.
A JPS spokesperson said the network is unable to provide information about individual patients due to state and federal privacy laws.
In-custody deaths attributed to natural causes are often preventable and can be the result of negligent care by jail and medical staff, according to Michele Deitch, director of the Prison and Jail Innovation Lab at UT Austin.
The Collin County Sheriff’s Office is investigating Yancy’s death, as well as that of Vernon Ramsey, who died in the Tarrant County jail in December as well.
Tensions ran high and in some cases erupted into violence during several Tarrant County Commissioners Court meetings following Yancy’s death.
This story was originally published March 27, 2025 at 2:19 PM.
