Shahid Walayat, of Thornton Street, Dewsbury, was jailed in 1993 for the murder of Julia Baines, and was sentenced to life in prison.
But upon his release in 2018, the victim of his sex abuse attacks reported her experience to West Yorkshire Police.
A jury at Leeds Crown Court found Walayat guilty of sexual assault following a trial.
The abuse began in 1989 when the victim was around six-year-old, and ended prior to 1992. She didn't see him after that following his arrest and conviction for murder.
The 48-year-old was unanimously found guilty of four counts of indecent assault and one count of indecency with a child on December 8. He was sentenced to six years in prison.
He was also issued with an indefinite restraining order against his victim.
West Yorkshire Police Detective Sue Marshall said: “Walayat is a dangerous sexual predator and assaulted his victim when she was a defenceless child.
“The victim was very courageous to come forward and report what he had done, especially due to cultural barriers, to seek justice for what he had done to her and we are pleased to see he will now face the consequences of his actions, a crime he thought he would be able to get away with. We hope this sentence brings our victim closure.
“We are here and ready to listen to anyone who would like to report offences of this nature. We will support you every step of the way and ensure that we investigate thoroughly and leave no stone unturned to bring the perpetrator to justice.”