A man was found dead in his cell at the Rowlett City Jail, according to police.
Anderson Howard, 25, was arrested and accused of driving while intoxicated early Friday.
Dispatch received a call around 4:30 a.m. of reports of a person driving while intoxicated, officials said.
Officers found a man asleep at the wheel of a white box truck in an apartment complex parking lot, Rowlett police said.
Police identified Howard as the driver and said officers were able to wake him at the scene.
Police allege he was intoxicated, in possession of marijuana and other controlled substances, according to a release.
After Howard was booked into the Rowlett City Jail, detention officers found him unresponsive during a routine check, police officials said.
Officers began CPR and called medics, who transported Howard to a local hospital. He was pronounced deceased at the hospital, police said.
Police said his cause of death is not known.
Texas Rangers are leading the investigation into Howard's death, according to Rowlett police officials.
