Wallace, now 37, eventually pleaded no contest to felony drunken driving with the proviso that he could appeal the question of whether the stop was legal. Which is why the Alaska Court of Appeals found itself pondering this weighty question.

According to a judgment issued by the court Wednesday, the Alaska State Troopers got a report about 11:15 p.m. June 21, 2001, that a man and woman were fighting in a car. The caller had the license number and approximate location of the vehicle, so trooper Lawrence Erickson was dispatched to investigate a possible domestic violence incident.

Headed north on the Steese Highway, Erickson noticed the blue Jeep Cherokee driving south. He turned around and followed and got close enough to confirm the plate was the same.

The Jeep stopped for a red light. Erickson was directly behind and could see into the Cherokee. At first he thought the man and woman were still fighting but "soon realized that the two were having a sexual encounter," the judgment says.

The woman in the passenger seat was facing the driver, her left leg on top of the driver's seat, wrapped around his head rest. "While trooper Erickson watched, Wallace 'got up and leaned over on top of the female passenger,' " the judgment says.

The light turned green. Wallace did not respond "for a few seconds." Then he sat back up and started to drive away. Erickson turned on his patrol lights, and Wallace stopped after about a block.