My husband was offered a deal but doesn't want to plead guilty to if he takes the deal can he have the verdict reversed after if he takes the deal?

Once a person pleads guity to a crime it becomes very dificut to fight the conviction.  Withdrawing the plea takes manifest injustice which is almost impossible to plead.  A mere assertion of innocence is not manifest injustice.  He is very likely to have counsel, in which case he should be addressing these questions to that person.  They will be in the best position to counsel him and give him advise based on his circumstances.  If he has been incarcerated 16 months pre-trial there may be timely trial issues as well that his attorney should be tracking.