Donna Lewis is a loose interpretation of an actual event which occurred in the Detroit area in the early 1980's. While driving down the freeway, a group of friends noticed that the doors of an armored car were swinging wide open. A large canvas bag became stuck under a car located directly between the security truck and themselves. The occupant took an exit ramp looking for a convenient place to stop.
Donna and her friends pulled up just as the occupant had dislodged the sack, the contents of which now lay spilled in smaller packets on the ground. The mystery person took off, but not before throwing some of the contents of the sack into the car. It is worth noting that this person never turned up again. According to the authorities, the mystery person made off with significantly more money than Donna and her friends gathered off the ground.
Alan's lyrics pretty much tell the story as it unfolded - except for the end - which he can not be held accountable for since the final chapter occurred after he wrote the song.
When Donna's former friends came up for trial, the judge said, "Finder's keepers", and let them walk - with the money!
Except for Donna Lewis, who had turned states evidence. Judge said that since she surrendered it to the authorities, she was not entitled to keep it.

Isn't it nice to know that some things actually turn out all right?!