The black crow and the name of the town is a direct reference to the demon and 7th spirit of The Lesser Key of Solomon , Aamon
The aerial view of a town shown in the first clip of the opening titles montage is not a town in Ohio, or even the United States. It is part of a town in the United Kingdom. Tell-tale signs include the style of houses and gardens, the street lighting, the European car models and - most conclusively - the British-style road markings, including a bus stop and a "driving on the left side of the road"-style "give way" junction marking.
Of the 68 cast members, 27 have appeared in Supernatural. From young "Dean" to the angel "Gadreel" to "Demon #3".
Both Emily Deschanel and Gerardo Celasco were in Bones. Deschanel played main character, Dr. Temperance Brennan and Celasco played in two episodes of the final season as Mark Kovac, a man who wanted to kill Dr. Brennan's family.
There is a "Wicked" poster in the girl's bedroom and they watch the movie "Vertigo". Both are stories with related themes to "Devil in Ohio".