Chief Russell Kerbow of the Lewisville Police Department confirmed that Tierney was arrested at around 4:20 a.m. in the 400 block of Bellaire after officers suspected the driver of the small SUV was intoxicated.
Tierney was taken to the Lewisville jail and transferred to the Denton County jail.
"We would do that on any investigation," said Lewisville Police Chief Kerbow when asked why Tierney was transferred to the county jail. "We want to make sure that the public appearance is transparent and above board."
Chief Kerbow also confirmed that someone else was in the SUV but wasn't arrested. Kerbow wouldn't say who the other person was in the car since the investigationis still open.
Calls to Tierney's city office were transferred to the City Managers office.
Assistant City Manager Donna Barron said the city had no formal statement since the incident is now a police matter.
Chief Kerbow's office said Tierney's charges are considered a Class B misdemeanor.
Tierney, 42, has declined to comment.
Lewisville public information officer James Kunke said Tierney resigned on Monday, the announcement was made during Monday night's city council meeting.