Mississippi Law

Scenario: A thriteen year old child is charged with Capital Murder in Mississppi. He is charged, prosecuted and convicted as an adult. He receives a 50 year sentence.

The State's attorney claims (publically) that the boy was offered a plea deal from the day of his indictment up to the day before the trial started which if accepted, would have kept him in prison for only 20 years.The boy and his attorney are claiming they were never offered a plea deal of any kind.

My question: would a plea offering have to be done at an official hearing? Would it have to be in writing? If the boys attorney was offered the plea deal and he did not convey this news to the boy, would that be grounds for ineffective counsel to regain a new trial?

What if the State's attorney is lying? How can this benefit the boy who states he was never offerd a plea when the State's Attorney has publically announced he had?

Lastly, this case is in the appeals process. Is this something that needs to be brought up now and proven before it is to late?