Lihai Vimahi, 23, and a co-accused Daniel Grech, 27, have faced an ACT Supreme Court trial over the shootings, which prosecutors say were targeted at properties occupied by rival club members.

It's alleged that about 9.45pm on March 12, 2015, the pair together drove by and shot at the window of a house in Kambah, and about 15 minutes later shot at a house in Stirling.

The Kambah house belonged to a member of the Rebels.

At the Stirling house, bullets struck a man, also connected to the Rebels, who was at the time sitting on the porch having a cigarette.

The pair have denied their involvement in the two shootings.

Mr Vimahi's brother was called by defence barrister Peter Bevan on Wednesday, where he took the stand to say his brother had been with him at home on the night of the alleged shootings.

The brother said he and Mr Vimahi had eaten dinner about 8pm or 9pm. Mr Vimahi had asked him to set an alarm for 4am, because he was joining the Comanchero National Run to Adelaide the next morning. They had watched TV and then gone to bed.

He said his brother Mr Vimahi would tell him stories about things he did with the Comanchero, but he tended not to believe him.

"He always wanted to big note himself," he said.

In cross-examination, prosecutor Mark Fernandez asked him if he was lying out of loyalty to Mr Vimahi, something the brother denied.

Mr Fernandez asked whether Mr Vimahi had been lying when he told police that he had been with his girlfriend that night.

The brother said: "I'm saying what I saw that night."

The prosecution also began its closing address on Wednesday. Mr Fernandez said the Crown case had relied on circumstantial evidence, including DNA and ballistics evidence.

He said Mr Grech's DNA was found on a .45 calibre pistol recovered near where Mr Grech was arrested in South Australia.

Ballistics evidence had linked the pistol to discharged rounds discovered at the Stirling home, as well as a bullet recovered from the shot man's shoulder, to the pistol, the prosecutor said.

In a recorded phone call while Mr Grech was in jail, the bikie had spoken about buying a pistol the day of the shooting, he said.

Mr Fernandz said Mr Vimahi had been linked to a sawn-off shotgun found at a Ngunnawal property. He said, for example, that photographs intercepted from Mr Vimahi's phone of a balaclava-clad man holding a sawn-off shotgun were of Mr Vimahi, as his tattoos matched those of the man in the photographs.

The court has heard discharged shotgun waddings were discovered at the scene of both shootings.

Defence barristers had yet to make their closing addresses.

Mr Vimahi faces one count of intentionally inflicting grievous bodily harm and one of discharging a firearm. Mr Grech is charged with the same two offences, as well as possessing a prohibited firearm.

The trial continues before Acting Justice Stephen Walmsley.