Define The Shaggy Defence Meaning

The Shaggy Defence
The defence favored by the protagonist in Shaggy's song "It Wasn't Me". Despite overwhelming evidence to the contrary, he maintains his innoncence by simply saying it was somebody else. Also liked by R. Kelly, O.J. Simpson, and Phil Specter

Person A: Oh, man, I just killed 2 dozen people. There were over 50 witnesses. My shirt was off and everyone saw my tattoo that says "My name is Jeffrey Dahmer". What should I do?
Person B: Say it wasn't you.
Person A: Oh, the Shaggy Defence...hadn't thought of that.
By Madelina