Homicide detectives were investigating how a bodyless head washed ashore on a South Florida beach.The man's head was found Tuesday by a beach worker in Key Biscayne, the barrier island just off Miami.There was no body attached to the head, Miami-Dade Police Department Detective Andre Martin said in an email Thursday.Detectives were awaiting results from the medical examiner, hoping that would lead to the identification of the man.Because the investigation is still open, authorities couldn't provide further details, according to the police department.