There was a time not so long ago when Lisa Steed’s stock as a corporal in the Utah Highway Patrol was soaring.

Passionate about police work, with a wide smile and a notable number of driving-under-the-influence arrests to show for her diligence, Corporal Steed was named trooper of the year by her superiors in 2007, her career seemingly heading toward the inevitable promotions.

In November, however, the once promising officer was fired amid a haze of misconduct allegations.

Though the Highway Patrol would not discuss Ms. Steed’s dismissal, a lawsuit claims she falsified dozens of those arrests during her 10-year career.

According to the suit, filed Dec. 14 in District Court in Salt Lake County, Ms. Steed made a career of pulling over drivers who she claimed were driving drunk or under the influence.