Jill Barron says she has been working with the town since soon after the Dec. 14 killings.
Her work includes treating New York firefighters after the Sept. 11, 2001, terrorist attacks.
She is working with Newtown Health Director Donna Culbert to strengthen the town's mental health support system and assess what the community needs.
First Selectwoman Pat Llodra says the need for a mental health consultant with expertise in trauma is critically important.
She says every member of the community and beyond was affected by the killings.