A Gambian national has been convicted of six rapes and one attempted rape over a period of two years
Abdoulie Alex Njie, 33, of no fixed address, attacked his victims between January 2003 and August 2005.
The jury at Stoke-on-Trent Crown Court failed to reach verdicts on two other rape charges and one of possessing an imitation firearm.
The judge ordered these to remain on file, and deferred sentence pending psychiatric reports.
Njie came to prominence in 2005 as he fought to stay in Britain as an asylum seeker.
Jurors heard that Njie, who was living in Stoke-on-Trent at the time, offered cash to many of his victims, who were prostitutes, but then refused to pay and forcefully raped them.
He grabbed one woman, who was not a prostitute, as she walked in Cobridge and dragged her into bushes before raping her.
Det Insp Guy Titchener, who led the investigation, said: "Njie is a very dangerous man who preyed on vulnerable women late at night.
"Njie subjected all of his victims to nasty, sustained attacks. He didn't limit his attacks to prostitutes, putting one young woman through a terrifying ordeal after dragging her off the pavement.
"I hope this case encourages other women, including prostitutes, who have been raped or sexually attacked to come forward and be reassured that Staffordshire Police will thoroughly investigate their complaints."
A Gambian immigrant has been accused of raping seven women in Britain