I've recently been following the case of boxer Felix Verdejo, who pleaded not guilty yesterday in killing of Keishla Rodríguez. Cádiz Martínez, a second person indicted in the killing, also pleaded not guilty.
According to the reports, this 2nd person (Cádiz Martínez) participated in the killing, and has been cooperating with the FBI. His testimony is a big part of the reason why the boxer was arrested.
My question: Why would he plead not guilty if he's cooperating with the FBI? Since the death penalty is being considered, I assumed that he gave testimony in order to plead guilty and get a reduced sentence.
But then I read that it's a formality to plead "not guilty", and that's why I posted the question.