Note: As confirmed by the American Film Institute, the film was never registered for copyright despite a proclamation appended to the screenwriter's opening credit. J.W. Ocker corroborates its public domain status in The New York Grimpendium: A Guide to Macabre and Ghastly Sites in New York State (2012), p. 167 (ISBN-978-0-881-50990-8). The film is available in its entirety on the Internet Archive.
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (50 p.m.a.), Mainland China (50 p.m.a., not Hong Kong or Macao), Germany (70 p.m.a.), Mexico (100 p.m.a.), Switzerland (70 p.m.a.), and other countries with individual treaties.