It doesnt follow the books at all. It uses Scooby Doo clues and nonsensical deductions and assumes that the audience is a group of morons, waiting for the detective that happens to have JUST the piece of equipment (that isnt used by detectives) to examine the little shard of parchment that AUTOMATICALLY leads them to the conclusion...
"I would have gotten away with it too if it hadnt been for you pesky kids and Scooby the quadriplegic!"