Ol’ Beelzebub was always a go to evil figure for filmmakers and Satanism was big business again in the late ‘60s/early ‘70s thanks mostly to ROSEMARY’S BABY (1968) and THE EXORCIST (1973). Producer Sandy Howard must have had his finger on the pulse as the first mention of THE DEVIL’S RAIN as a potential project of his came in a December 5, 1973 issue of Variety, a few weeks before the aforementioned EXORCIST caused a phenomenon in the United States. The worldwide tallies for that film must have certainly influenced the shady distributor Bryanston Pictures to announce in June 1974 that they were going to finance and distribute the picture with Howard. Headed by the mafia-connected Peraino family, Bryanston had made bank on the X-rated features DEEP THROAT (1972) and THE DEVIL IN MISS JONES (1973) and were looking to expand their horizons (they would score their first massive mainstream hit in late ’74 with Tobe Hooper’s THE TEXAS CHAINSAW MASSACRE). Seriously, if you’re making a film about a deal with the devil who better to fund the film than the mob? In the press release the script was credited to Gabe Essoe and Jim Ashton. By the time the film was in production, a third screenwriter, Gerald Hopman, was also credited.
JAWS leaves THE DEVIL'S RAIN in its wake: