Thank you for your question. Please permit me to assist you with your concerns.
The answer here will be a bit detailed as it is not a clear yes/no answer, so I ask you to bear with me. If the answer is not as you hoped, please do not blame the messenger.
Family court and criminal court are somewhat different. In Family the judges are tasked with making decisions based on it being 'in the best interest' of the child. Family courts tend to be far more permissive as they tend to look at multiple facts and factors as far as 'fitness'--they can and do look at past history of abuse or neglect, domestic violence
, drug use, alcohol abuse, history of mental illness, history of criminal behavior and criminality, and moral turpitude. Now, a good attorney on your end can claim that anything beyond 10 years is prejudicial and not valid because it was simply an accusation and not a conviction, so that should be kept out, but a judge can still find it to be important enough to evaluate it. Since it is not a 'right' as far as having custody, and the judge is looking out for the best interest of the child
, even past information, information that in most courts would be seen as hearsay and inadmissible could still be evaluated by the the judge. So yes, a Judge can indeed do that, but based on the type of the accusation and the lack of conviction a good attorney on your side should be able to appeal it and claim that it was not something that a responsible judge should consider as part of his decision making process.