A second investigation is underway into the death of an inmate in the Hidalgo County jail. The 25-year-old inmate died hours after after suffering a series of seizures early Saturday morning. He was pronounced dead at Edinburg Regional Hospital. The man had been arrested Wednesday by Mission police and booked into the jail on a charge of aggravated assault with a deadly weapon. A preliminary investigation by the Hidalgo County Sheriff’s Department found no signs of foul play in the inmate’s death. A further investigation is being conducted by Texas Rangers. Results of an autopsy are pending.