On Thursday night, police began searching the shoreline along Powells Cove Blvd. in Whitestone after a 14-year-old girl found the skeletal remains of a left arm. Police also found legs and articles of clothing, including a dark pair of size-5½ sneakers, according to the Post’s law enforcement sources. That fits the description of what Avonte Oquendo, a 14-year-old autistic boy, was wearing wearing when he went missing in October, and police are said to be considering a possible link. It’s a horrific discovery either way, but hopefully this will turn out to be another false lead in the search for the boy.