** FILE ** Addison Strychalsky, 2, of Newtown, Conn., pets Libby, a golden retriever therapy dog, during a visit from the dogs and their handlers to a memorial for the Sandy Hook Elementary School shooting victims on Tuesday, Dec. 18, 2012. (AP Photo/David Goldman)

Photo by: David Goldman

** FILE ** Addison Strychalsky, 2, of Newtown, Conn., pets Libby, a golden retriever therapy dog, during a visit from the dogs and their handlers to a memorial for the Sandy Hook Elementary School shooting victims on Tuesday, Dec. 18, 2012. (AP Photo/David Goldman)