The hunt for a man who terrorized California for a decade became an obsession for Michelle McNamara. The true-crime writer thought she was close to finding him before she died unexpectedly. Now, her husband and others are working to finish a book she started on the case. Correspondent Tracy Smith joins "CBS This Morning" to preview "The Golden State Killer," an all-new "48 Hours" airing Saturday at 10/9c on CBS.
