Shep Houghton

Hi. I wonder if you can tell me what kind of source that were used to confirm the death of Shep Houghton http://www.imdb.com/name/nm0396473/. According to his profile he died on December 15, 2016 but there is no obituary or anything on the entire internet that confirms the death and since you can't add death date to a person without citing a source I would like to know what kind of source that were used.