Police are investigating the death of a 25-year-old man at Rowlett City Jail on Friday.
According to the Rowlett Police Department, officers responded to a call about a person driving while intoxicated at approximately 4:36 a.m.
Police said officers located the vehicle, a white box truck, stopped in the parking lot of an apartment complex with the driver asleep at the wheel.
Officers woke up the driver, 25-year-old Anderson Howard, and arrested him for driving while intoxicated, police said.
Police said that after their investigation, Howard was also charged with possession of marijuana and other controlled substances.
Howard was processed into the Rowlett City Jail, police said.
According to police, Rowlett Detention Officers found Howard unresponsive in his cell during routine checks.
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Police said Detention Officers began performing CPR on Howard and notified Rowlett Emergency Medical Services.
Rowlett EMS transported Howard to an area hospital where he was later pronounced dead, police said.
Police said Howard's cause of death is unknown at this time.
An investigation by the Texas Rangers is ongoing, police said.