An emotional Emilija Dilber told a Supreme Court jury on Thursday her friend, Sarah Johnson-Portelli, 20, had been sitting on the Queen-sized bed talking when she was shot in the head in the early hours of April 7, 2013.

Ms Dilber claimed "everything just stopped" and she turned and saw Jovan Jojic holding the shotgun.

She said another man, who cannot be named, asked Mr Jojic, "What have you done?"

Mr Jojic allegedly replied, "I didn't know it was loaded."

Cross-examined by defence barrister Wayne Toohey, representing Mr Jojic who has pleaded not guilty to one count of manslaughter, Ms Dilber admitted she had been smoking ice but denied being out of her mind on drugs at the time. Ms Dilber agreed she had been using ice for up to two years before the shooting.

Mr Toohey has told the jury the major issue during the trial would be who was holding the shotgun when it discharged.

Mr Jojic claimed he wasn't even in the room when the shot was fired.

"We, the defence, say that he was in the kitchen at the sink at the time of that shot ringing out," Mr Toohey said.

Ms Dilber said the other man had brought out the handgun and shotgun when they were in the bedroom and he and Mr Jojic were loading and unloading them.

Sarah Johnson-Portelli was shot in a St Albans bedroom in 2013. Photo: Facebook

She said there was no tension in the room and everyone was in a good mood before Ms Johnson-Portelli was shot and slowly slid off the bed.

Ms Dilber said she ran out of the bedroom and just kept "running and running" after hearing a second gunshot.

Crown prosecutor Mark Rochford, QC, has told the jury that when Mr Jojic left the bedroom, the other man called out to him, "Come back, help',' before walking out into the hallway.

"The accused [Mr Jojic] was in the hallway and was still holding the shotgun. He fired a shot into the floor. The pellets ricocheted into the left leg of [the other man]."

Mr Rochford said the injured man's brother heard the shotgun go off and tried to help Ms Johnson-Portelli as he called triple 0.

Police and paramedics arrived at the house but found Ms Johnson-Portelli dead in the bedroom.

The Supreme Court was told that, before her death, Sarah Johnson-Portelli and her friends had been smoking ice in a St Albans bedroom.  Photo: Facebook

"It's the Crown case the accused man was handling and operating a loaded shotgun and he discharged the shotgun," Mr Rochford said. "He made it go off."

The prosecutor said the Crown was not claiming Mr Jojic intended to kill or seriously injure Ms Johnson-Portelli, but his dangerous actions caused her death.

Mr Toohey said Mr Jojic never heard anyone call out to him because "he was well and truly out of that house almost straight after the panicked Ms Dilber".

"He himself became afraid and panicked after he heard the almighty bang. There was no one else in the kitchen or the hall when Mr Jojic left."

"The assertion by the prosecution that Mr Jojic left that address with the shotgun and another firearm is completely denied by the defence. He arrived at that address with nothing in his hands and he left that address with nothing in his hands."

The trial, before Justice Michael Croucher, continues.