"Control seemed to be his aim..and showing his superiority.
I imagine that he is talking to police, if he is talking, in order to impress them with his brilliance."
I'm no profiler, but I have read my share of true crime novels and this stuff fascinates me.
John Wayne Gacy and the Hillside Stranglers also liked to demonstrate their superiority. In both cases, they impersonated police officers. Gacy was a pathological liar who was always bragging about things he did and people he knew.
When Gacy was caught, he demonstrated his "brilliance" by drawing a detailed map of the graveyard under his house and how all the bodies were arranged. He got a charge out of rattling on and on, which proved troublesome later when he tried to plead not guilty.
BTK also seemed to thrive on his authority position. His uniform even has a law enforcement officer look to it.
Hopefully he is spilling the beans to feed his sense of self-importance.
And I wouldn't mind too terribly much if he spilled the beans on a post-1994 murder. Otherwise, he'll sit in jail the rest of his life and play the hero. Bring back the chain gangs.