MIDDLETON, Wis. (AP) -- Police say a Sauk City woman who was arrested on suspicion of drunken driving had her 2-month-old son in the vehicle.

Middleton police say the woman was arrested early Saturday morning for what would be her third-offense of driving while intoxicated.

Police pulled over the 28-year-old for allegedly driving 75 mph in a 55-mph zone. A preliminary breath test said her blood-alcohol level was 0.18 percent, more than twice the legal limit.

Her son was secured in a safety seat. Because the driver had a child passenger, the alleged offense would become a felony.

The baby was taken into protective custody. He slept in a police lieutenant's office until his grandmother arrived.