State Troopers in Frederick involved in a four-hour, DUI saturation patrol between 11:00 PM Sunday and 3:00 AM Monday stopped 20 vehicles. Out of the 20, four were put through field sobriety tests, and three were arrested for DUI, according to officials at the Frederick Barrack.

15 traffic citations were also issued, along with 12 warnings and two safety equipment repair orders.

The operation took place along the Route 15 and I-270 corridors.  It involved the use of marked patrol cars and uniformed troopers.