Prosecutors have described the 2003 armed rape of an Adelaide Hills mother while she slept as one of the worst of its kind because the rapist was "on the hunt" when he attacked his victim.

Key points: Anthony William O'Connor was linked to the 2003 rape by DNA 15 years later

Anthony William O'Connor was linked to the 2003 rape by DNA 15 years later Prosecutor Sandi McDonald said it was "hard to envisage a more serious category of rape"

Prosecutor Sandi McDonald said it was "hard to envisage a more serious category of rape" O'Connor will be sentenced later this month

District Court Judge Paul Muscat will sentence Anthony William O'Connor, 53, later this month.

"It quite simply does not get any worse than this," prosecutor Sandi McDonald SC told the court today.

"The prosecution case was that this man was on the hunt to rape that night. It is hard to envisage a more serious category of rape."

O'Connor was armed with a knife when he broke into the victim's house as she slept, blindfolded her and violently raped her in September 2003.

The case went unsolved for about 15 years until O'Connor was linked to the crime by DNA.

A District Court jury unanimously found him guilty of three counts of rape and a charge of aggravated serious criminal trespass.

DNA found on items at the scene matched DNA from a mouth swab taken from O'Connor.

The jury heard the DNA found on items at the crime scene was 3.1 billion times more likely to belong to O'Connor than another person.

Victim experiences 'emotional triggers' in everyday life

In her victim impact statement read to the court by prosecutors, the victim said she suffers from "shock, fear, grief, distress and embarrassment".

"Any sounds or noises I hear from inside, I suffer from insomnia and nightmares," she wrote.

"Until conviction, I had a constant fear of the person still being out there and a fear of seeing someone who resembled his description."

She told the court that emotional triggers were scattered in everyday life, including certain written words, words expressed by people, media and the sight of blood.

"I struggle with the sight of knives," she said.

"This has affected my relationship with males — I cannot be physically close to unknown males, such as standing in a queue.

"I am wary of any possible violent behaviour."

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She said she suffered a large cut to her hand from the knife O'Connor used in the attack.

"He cut through tendons and I required months of rehabilitation and physiotherapy by a hand specialist at Royal Adelaide Hospital," she said.

"I have ongoing stiffness and sometimes aches.

"The scar on my hand is a constant reminder — I feel self-conscious when accepting change of other circumstances where people may see it."

O'Connor's lawyer told the court that his client had lived most of his life interstate but would come back to South Australia from "time-to-time" to source cannabis.

He migrated from Ireland to Australia in 1985 and could be deported back following his release from jail.

"He does not accept the verdict," his lawyer told the court.