DNA evidence 'most likely' came from Canberra murder accused Vojneski: forensic scientist

Blood found in the home of a slain Canberra woman was 18 billion times more likely to have come from the accused murderer than anyone else, a forensic scientist says.

Aleksander Vojneski, 31, is on trial accused of killing his girlfriend, 30-year-old Paula Conlon, in her Macgregor home two years ago by stabbing her eleven times in a frenzied attack.

An ACT Supreme Court jury heard today that a forensic scientist tested a small amount of blood from the door handle and hallway floor of Conlan's home and found that when compared with the rest of Australia's Caucasian population, the blood was most likely to have come from Vojneski.

But Vojneski's lawyer questioned the method used to identify the DNA samples at the house as belonging to his client.

The court heard the relationship between Vojneski and Conlan was violent from the start.

The jury heard Vojneski had a long history with alcohol and drugs, and that alcohol increased his risk of becoming angry and aggressive.

The court was also told that on one occasion Ms Conlan had bruising and told a friend it had happened when Vojneski held her over a balcony.

In summing up, prosecutor Shane Drumgold told the jury he had a strong circumstantial case and there was evidence from Conlon's friends about violence between the pair.

"I would suggest this was a cycle that dominated this relationship," he said.

Mr Drumgold reminded the jurors of evidence given at the beginning of the case outlining other incidents where Vojneski had stabbed someone, and attacked his mother.

Earlier, the court heard evidence from Vojneski's brother, who told the jury he thought his brother may have been delusional the weekend before the murder.

He told the court he often gave Vojneski money knowing he would buy drugs, to keep him off his back.

He said Vojneski's mental health improved for several years through treatment if he stayed away from alcohol and drugs, but that he had made a "strange comment" about being owed money by someone on the weekend before the killing.

Vojneski's brother denied lying to the court, after giving answers that were inconsistent with the evidence of other witnesses.

The trial has been running for almost four weeks.

The defence has offered no evidence in the case and closing submissions will continue on Thursday.