Roger Vella Jr. - the mob associate who wanted to go back to prison to be with Joey Merlino - is the lead suspect in the Oct. 22 gangland slaying of onetime mob consigliere Ronald Turchi, say law enforcement sources.

The night before Turchi disappeared, Vella, 28, ate dinner with Turchi, 61, at the Saloon, a South Philadelphia restaurant, two witnesses said.

Turchi, demoted to soldier, and Vella were allegedly associated with a sports gambling business in South Philadelphia with reputed mob associate Anthony Staino, said street and law enforcement sources.