Sgt. Ken Williams gets a knock on his door one morning, and it's a young woman saying she knows Williams' aunt. She's very chatty and very flirty, and before Williams knows it he's late leaving to report for work at Highway Patrol. He makes a date with the woman for dinner and then they both leave the apartment.
While Williams has been talking to the girl, a man has taken his car, run down a pedestrian, stopped on the other side of the intersection where the accident occurred so witnesses can get a good look - He's in uniform - and then speeds away. When Williams gets to work he discovers the hit and run driver's license plate was the same as his own, plus he has no alibi since nobody of the same name as the girl he spoke with is at the hotel she said that she was staying at.
Williams has been set up by the brother of a man he helped send to prison for life the previous year, with the chatty girl that stopped by being the girlfriend of the brother, but nobody knows that. Dan Matthews assumes it's a set up and probably has something to do with Williams' work, but it could literally be the friends or family of dozens of defendants. How Matthews and Williams narrow down who it had to be starting with the only place that Williams was unable to lock his car during the past week or two (and thus get his car keys stolen and copied) is an interesting look into police work, as usual.
It was unusual for Highway Patrol to "get personal" as having the case of the week intersect or in this case be about one of the regular cast, but it worked well.