Ashley McDowell, of no fixed address, was convicted by a jury at Bristol Crown Court of sexually assaulting a woman in her late teens in 2013 following a trial last month.
The 39-year-old was also found guilty of sexual activity with a teenage girl and attempting to incite the sexual exploitation of another teenage girl in 2019.
He was sentenced at the same court on Tuesday (March 14).
During the trial the court heard McDowell assaulted a woman in 2013 after offering her a lift home from a night out.
The incident was investigated at the time however police were unable to identify a suspect.
Six years later, while investigating sexual offences against two teenage girls, officers found evidence linking McDowell to the 2013 assault including screenshots he’d taken of a social media post in which a member of the public warned women of a man’s predatory behaviour and someone had subsequently identified him in the comments.
During the examination of his phone, officers also found messages McDowell had sent a 16-year-old girl offering her money in exchange for sex and offers to buy her trainers and alcohol.
McDowell, who defended himself in court, was found guilty of attempting to incite the sexual exploitation of a child and sexual activity without consent after his DNA was found on the clothing of a missing girl who officers found unconscious in his bed.
Detective Sergeant Harriet Drewett said: “Ashley McDowell is a predator who has taken advantage of vulnerable women and girls over a number of years.
“We will never give up pursuing dangerous offenders like him and I hope this case demonstrates to the public no case is ever closed.
“I’d like to thank all the victims in this case for the support they have shown us throughout our investigations and during the court proceedings.
“If you have been affected by this inquiry then please don’t hesitate to contact us. You will be believed and we will always support you and seek to get you the justice you deserve no matter how much time has passed.”