Guy Gardener wrote:
He has a tracking tag inside his shoulder that can only be removed surgically.
And if he removes it, the deal is off.
I had forgotten about that, actually.
It's been said that since he knows most of the people on the Black List through his criminal dealings, that in order to hide the fact that Reddington's working for the FBI, he is to remain his criminal activities, lest he tip someone off.
A bit hard to swallow, but like I said: for this show you really have to suspend your disbelief to enjoy it. And I enjoy it, so I must be doing something right.