I see Rubadub's point - by what mechcanism do the elders alert the congregation that there is a pedophile in their midst?
It is a matter of priorities - if safeguarding the cildren is your utmost concern, then the details can be worked out. But, it is extremely important that those in positions of power understand the nature of pedophilia and the intractability of the aberration. It must be understood that warnings, threats, and sanctions are not deterrents and that the emphasis on 'repentance' is dangerously naive.
I think that congregations can be as straightfoward as they need to be to protect children. If a registered sex offender is in the congregation, he is already subject to public exposure (no pun) through the registry. One avenue would be for the elders to approach individually and privately every family with vulnerable children and warn them.
OTOH, if they really want to protect children, known predators should not be allowed in the KH, where they might end up sitting near a vulnerable child. Predators are not supposed to be near children - it is usually considered a violation of their terms of parole.
Here's the registry of this particular offender, Johnathan Kendrick: