TARRANT COUNTY, Texas – Civil rights activists in North Texas are calling for answers after the latest in-custody death at the Tarrant County Jail. Mason Yancy, a 31-year-old activist and co-founder of Open Carry Texas, passed away on Dec. 27 after being transferred to the Tarrant County Jail by Grapevine Police. Yancy was arrested on Christmas Eve for possession of narcotics and drug paraphernalia.