The 25-year-old then ditches his car and runs along the street towards the victim before picking up the weapon he used to kill her – a metal fire hydrant cover weighing 7.8 kilograms.
In the footage neighbour Lisa Kennedy can be seen fleeing from her house and attempting to help the mother-of-one escape.
“I was screaming obscenities at him, screaming for help to try and stop him,” Kennedy told Nine News.
At first, witnesses claim they believed Patea was trying to assist Brown following the crash, but after hearing the 24-year-old's cries they quickly realised her estranged boyfriend was trying to harm her.
“She was upside down and I couldn’t help her, so I thought I would go ring the police and ambulance,” witness Edward Harding told 7News.
After striking her 16 times and fighting off those that tried to stop him, Patea left the heavy metal slab on his former lover’s face.
In the vision, he then proceeds to calmly walk away and leave the scene in a council vehicle.
“What I saw you do to Tara horrified me to my core,” Kennedy said in court at Patea’s sentencing.
“It was a domestic violence situation that resulted in you beating to death a woman as she lay trapped in her car unable to help herself.”
Patea was sentenced for life for the murder of Brown after pleading guilty on the first day of his trial.
You can see the footage here. Warning: Graphic content.
This article first published on New Idea.