Video report by Martin Fisher
Gary Allen has been jailed for life with a minimum of 37 years for the murders of Samantha Class in Hull in 1997 and Alena Grlakova in Rotherham in 2018.
Allen was found guilty of the two murders at Sheffield Crown Court last week, having previously been acquitted of the killing of Ms Class in 2000.
His acquittal for murder was overturned in 2019 by the Court of Appeal after a range of new evidence was presented - including the murder of Ms Grlakova and a confession made by Allen during an undercover operation by Humberside Police between 2010 and 2012.
The Honourable Mr Justice Goose said when sentencing Allen: "You have been convicted of the murders of two women 21 years apart.
"You thought you had got away with murder, but today your past has caught up with you. This jury has, on overwhelming evidence, convicted you on both murders.
"You are an extremely dangerous man with a long-held, deep-seated, warped view of women, in particular sex workers.
"It would not be an overstatement to say that what you did to those two women and the suffering to their families was wicked."
Detective Chief Inspector Christine Calvert, from Humberside Police, said: "Gary Allen is an extremely dangerous man, particularly to women, and is now exactly where he belongs, in prison.
"Samantha and Alena’s children are without a mum because of what this man did, and he is yet to show any remorse for his actions.
"Their families have waited a long time for this moment, to know that Gary Allen will be behind bars for the rest of his life, unable to cause any further harm and break up anymore family units."
Police forces around the UK have been asked to check on unsolved cases to make sure Allen - who has professed a deep-seated hatred for women, and sex workers in particular - has not committed any further offences.
The National Crime Agency is assisting forces in the region in their search for historical crimes that could have been committed by Allen.
The appeal for the retrial into Allen's killing of Samantha Class was led by the Director of Public Prosecutions who described him as "evil".
The case was the first "double jeopardy" case, a rule that once a jury has pronounced a not guilty verdict there can never be a second chance unless there is compelling new evidence, of its kind for Humberside and South Yorkshire Police forces.Allen has previously been jailed for attacking two women in Plymouth in 2000.