Inspector Laurence Rankin, in Canada, said Farley had been "picked up" earlier this month by Canadian Border Services Agency for violating immigration laws, the Huffington Post reported.
He was subsequently investigated as a suspect before being being charged with the March 4 offence against the sex worker.
"We knew we had a particularly horrific case of kidnapping and we wanted to take every step possible to find the attacker," Mr Rankin said.
Officers allege the 42-year-old victim was picked up against her will, driven to a secluded area, tied up and beaten during the incident, the Huffington Post said.
Several witnesses called 911 as they watched the woman being dragged behind a white van down a city street.
Police believe the woman partially freed herself and, fearing for her life, attempted to jump from the moving vehicle.
The woman, who has since been released from hospital, suffered serious injuries, including to her head, but was able to give a description of her attacker.
Farley is charged with eight offences, including aggravated sexual assault, assault causing bodily harm and kidnapping.
He is yet to face court.
