The whole point of a plea deal is to give a more lenient sentence in exchange for admitting guilt. If that wasn't the case everyone would just go to trial for everything, there's always a chance of getting out.
In theory. In practice, extreme punishments, along with penury from the costs of a defense, have to be threatened because the CJ system has lost the ability to deliver justice at trial.
Under current policies, that results in more lenient punishment than the innocent who fight their charges. So, yes, try them.
Where is the money for that going to come from? Ending the Drug War would cut the number of criminal cases by more than half.