Use the most common distinction that almost everyone has experience with, to explain the difference. Two cars collide at an intersection. Investigating police either cannt determine who was at fault, or charge one driver with failing to yield but that driver is found not guilty.
Does the lack of a criminal guilt finding prevent in any way any subsequent civil claim? Absolutely. Both drivers can sue the other, and have at it in civil court. That's the same distinction between O.J. (criminal) and O.J. (civil).
Congressman Billybob
Latest column, now up on UPI, and FR, "The Berlin Solution to the Baghdad Problem."