A man had the "objective" of dislodging his partner from a moving car when he allegedly murdered her, a court has heard.
Michael O'Connell, 43, faced the seventh day of his ACT Supreme Court trial on Thursday, during which the prosecution and defence delivered closing addresses.
The man has pleaded not guilty to murdering "the love of his life", Danielle Jordan, by allegedly driving at speed, causing the woman to fall from the bonnet of his car and suffer a fatal head injury.
The jury must also consider manslaughter as an alternative.
Opposing parties in the trial disagree about the circumstances around Ms Jordan's fall from the black Mitsubishi Triton in the early hours of April 15, 2022.
In determining O'Connell's guilt, the jury must decide whether the prosecution proved beyond a reasonable doubt Ms Jordan was on the bonnet of the car before she fell and that the accused man knew where she was positioned.
The court previously heard the pair had been arguing at a Melba apartment throughout the morning and the woman was attempting to stop the alleged offender from leaving.
"It was his intention to keep going at speed over a distance until Ms Jordan was dislodged and had contacted the road," prosecutor Mike Smith said.
To support this, he cited an account from the case's only eyewitness, a 13-year-old girl who was spending the night at the deceased woman's apartment on the night in question.
The teenager told police she witnessed the deceased woman on the front bonnet of the vehicle as it drove away from Ms Jordan's home, around the corner and out of sight.
"She heard a scream and a doof," Mr Smith said.
She then claimed to have caught up on foot to the scene, seeing from a distance O'Connell picking up Ms Jordan's body and carrying her behind the vehicle to place her in the passenger seat.
"She presents as articulate, switched on and making absolutely no attempt whatsoever to dissemble or dodge or spin an answer," Mr Smith said of the witness.
The girl previously recounted O'Connell telling her "I shouldn't have done it" hours after the incident, with Mr Smith claiming "it" could only be the accused driving at speed with the deceased woman on his bonnet.
The prosecutor said the teenager's account of the morning lined up with evidence and CCTV, and was consistent, as opposed to O'Connell's version of events, which he described as a "moving feast".
Defence barrister Jon White SC directly contradicted this claim, asking jurors to question the key witness' reliability and telling the group they "must have a doubt" about where Ms Jordan was located on the car.
He said errors in the teenager's evidence, such as where the incident occurred and where she was located, hearing a separate "doof" sound, or where the car drove, supported this.
The court heard again on Thursday O'Connell's version of events through a phone call he made a week after the incident.
In the recorded call, the man said he thought Ms Jordan had hopped off the bonnet before he drove away.
He claimed she then jumped on the ute's back tray but he only noticed this while driving, before seeing her, slowing down and stopping once she fell off.
This was the man's third version of events, with him first telling hospital staff the deceased woman had fallen down her back stairs and then informing police she had caught up to the stationary car, jumped on and fallen off.
"I f---ing lied in the first place, that's f---ed me up a bit," he said.
While Mr White said evidence showed the car had been driving at just over 50kmh before it stopped, there was nothing to suggest O'Connell had swerved, driven erratically or braked to dislodge the woman.
"How does that fit with the Crown case that he had a murderous intent?" the barrister asked.
The opposing parties also disagreed about O'Connell's demeanour after he exited the car, when he told the 13-year-old girl he was "sorry" and "she just fell off, I don't know what happened".
The defence barrister said his client's shock and anger, the tone of which could be heard on CCTV, turned to "not just concern but despair" after realising what had happened.
The prosecutor said the man's anger turned to "panic and then regret" when the "reality of what has done begins to dawn on him".
Mr White is set to finish his closing address on Friday.
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