Ryan Chinnery carried out the sex attacks near his Ashford home
A Kent teenager who had an "unhealthy interest" in pornography has been jailed indefinitely after carrying out late night sex attacks on women.
Ryan Chinnery, 19, of Christopher Bushell Way, Ashford, was told he would serve at least four years in prison before being considered for release.
He admitted two sex attacks. The prosecution agreed to leave two other charges on the court file.
Maidstone Crown Court had heard he also indulged in drink and strong cannabis.
The court was told he would spend many hours playing the violent computer game Grand Theft Auto in which players steal cars and kill prostitutes.
"It is right to observe there is a worrying mirror of conduct between that which the pornography presented to you and that which you carried out," Judge Philip Statman told Chinnery.
The judge said video games such as Grand Theft Auto "seem to show scant respect for women".
"It cannot have helped him in all the circumstances of this case," he said.
The court had heard Chinnery carried out the two offences near his home in July and August 2007.
One of the attacks was so violent the woman broke her arm and in another Chinnery and his victim fell down a river bank into the water.
Judge Statman said that each of two offences, carried out when Chinnery was 18, displayed "planning and premeditation".
He added: "Both of your victims were women walking home alone at night and they were vulnerable."
He said one of the most troubling aspects of the case was that Chinnery appeared to be a "perfectly normal young man" with a responsible family, job and girlfriend of two years.
He said: "You were loved and respected by those who knew you, but there was another side to your personality hidden from those who loved you - an unhealthy interest in pornographic material."
He praised the bravery of Chinnery's victims.
Referring to one, who gave evidence in court, he said: "It was clear she was reliving the ordeal of that day, at times close to tears."
Chinnery was also disqualified from working with children and ordered to be placed on the sex offenders register for life.
Ryan Chinnery, from Ashford, played a game called Grand Theft Auto which allows players to attack sex workers