Mechanism for reaction of aryl diazonium with potassium iodide

I’m working on a synthesis problem that requires me to draw the arrow mechanism for the second half of the Sandmeyer reaction. Basically it’s the halogenation of an aryl diazonium compound. Typically it’s done using a copper catalyst, but it can also be done using just potassium or sodium iodide. Problem is, I can’t find any reference showing how this works in an arrow pushing mechanism. Does anyone know where I could find an example to show me how it works?

• Well, it's probably SN1 so not much of writing ;) May 6 '18 at 23:15
• I was taught that it's a radical mechanism, and that makes sense because if it was a pure SN1 then this would work with chloride ion too, but you need CuCl (not just NaCl) for that May 6 '18 at 23:22