If they have arrested him then it is past the point where it can be headed off by pointing out that the child has lied now and in the past. He has to get an attorney and save that for a trial
. The days when someone could get one of these cases resolved by a good plea bargain are long gone. Now any type of plea bargain will include sex offender registration, restricted or no visitation, a felony record, etc.
The case might have been able to be stopped if he had hired an attorney when he was accused initially or even before this arrest, but once an arrest has occurred the DA is extremely unlikely to back off because of the political repercussions.
Polygraph tests are not admissible in court and so most of the evidence that he will be able to use will be contaminated by the police or "child therapist" interviewers. The lawyer will have to begin gathering the evidence and getting it ready to go to trial.
If he cannot afford a lawyer then the court will appoint one but if he has the means then he should definitely look around for a lawyer that has fought and beaten these kind of cases before. Unfortunately, it is almost certainly going to take a trial to do so.
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