A masked rapist who violently attacked two girls in the mid 1990s has been jailed for at least a decade.

Paul Michael Radford, 44, pleaded guilty last year to raping the girls in April and November 1994.

He was arrested in 2009 for indecently exposing himself to teenage girls and his DNA matched him to the earlier crimes.

The Adelaide District Court heard the first victim was 14 when she was playing in the yard of a southern suburbs primary school and Radford dragged her between two classrooms.

He bound her hands and mouth with tape and raped her while wearing a type of balaclava.

Six months later he raped a second girl in parklands at Bedford Park, also while wearing a balaclava.

The court heard Radford struggled with the girl before the rape.

Detective Brevet Sergeant Terry McCormack of Sturt CIB said the second rape victim, who had since moved interstate, still wanted to find and thank a good Samaritan who went to her aid that night.

"She couldn't be here today for the sentencing but she wants to put out a request - back in November 1994 when she was sexually assaulted in the parklands at Bedford Park, off of Sturt Road leading to the Science Centre, a passerby stopped and assisted her and called for police," he said.

"This victim would like to put out a request that if this person remembers the incident if he could come forward she'd like to thank him personally.

"He took her across to the ambulance station across the road from the Sturt Police Station, which is adjacent to where the offence happened, and he waited with her until the police arrived to assist. But then he left after that without giving his details.

"It's very important [to her], it's closure, she couldn't be here for the final day at court itself because she currently lives interstate but it's part of closure to her [that] she'd like to speak to this person and to thank him personally."

Sorry, this video has expired DNA catches masked rapist ( Candice Marcus )

Years of stress

Outside court, the victim of the first rape, who did not wish to be identified publicly, said she was happy with the sentence imposed.

"For the 18 years I've had to go through, I think that it is a good sentence and I hope that he finally takes responsibility for what he has done," she said.

"Even with a DNA match to two crimes, [it] was allowed for the case to go on for three years. I lost a job because of it, [there was] a lot of stress.

"I don't live in Adelaide any more so it's been constant travel. I think this will give me closure but it's not going to erase what has happened in the past. Large parts of my childhood I have just blocked out because it's just been that painful."

She spoke of the hatred she felt.

"For so many years it was just a lot of hate. Because he was wearing a mask at the time I had no idea who I was hating, so it was good to put a face to the person," she said.

"I just hope that he goes to prison, he takes whatever treatment and hopefully he comes out a better person for his family."

Memory loss questioned

During sentencing, Judge Peter Herriman questioned Radford's level of remorse and willingness to accept responsibility for his crimes.

"It was violent, it was aggravated by the fact that it was perpetrated on very young girls who were strangers and in vulnerable places," he told the court.

"It is clear it has had a lasting impact on their lives and that impact has been aggravated by the substantial time that elapsed before you were brought to justice.

"I have reservations as to your levels of rehabilitation and remorse. You're still not prepared to fully accept responsibility for your actions.

"You've pleaded guilty and apologised to your victims but in that letter of apology you say you had no memory whatsoever of committing these offences.

"I queried your claim of loss of memory because of the lack of any psychiatric diagnosis to explain it."

Judge Herriman said had it not been for Radford's guilty pleas he would have imposed a head sentence of 18 years in jail.

He reduced that to 16 years and imposed a non-parole term of 10 years.

Radford has been in custody since his arrest in 2009.