Simpson is charged with two charges of intimidating his neighbours Rebekah and James Brown between August 7, 2012 and September 21, 2012. It is claimed the neighbours fell out over a baby-sitting arrangement.
"The whole time I was getting the girls out of the car, I kept glimpsing over and he was standing there watching," Mrs Brown told the court.
She told police prosecutor Sergeant Grant Gerken that Simpson also allegedly went to her place of work once and stared at her while she worked.
She said she felt scared and intimidated by Simpson's behaviour and was constantly on edge about what he would do next.
The couple alerted the police after the first incident, but as the alleged intimidation continued, and their 4-year-old daughter started refusing to leave the house because she was scared, she and her husband felt so unsafe in their home they at one point sent their children to stay with their grandparents for six weeks.
Mr Brown said the incidents happened regularly, with the couple noting in a diary the worst or extended incidents.
A Child, Youth and Family social worker gave evidence that he, too, had witnessed intimidating behaviour from Simpson after he came out and stared at him in an "intensive, invasive and unsettling" manner as the social worker was dropping Mr Brown home.
The social worker had called in on the Browns unannounced after someone reported to CYF that there were issues with hygiene at the Browns' house and a lack of attachment between the parents and the children - none of which he found any evidence of, in fact only evidence to the contrary, the social worker told the court.
"I noticed a very good rapport and attachment between parent and child ...between both parents."
Mr Brown's mother, Sarah Brown, said she, too, had been the subject of long stares from Simpson, who, she said, had stood at his lounge windows in a "very aggressive stance" and stared at her several times so that she felt quite uneasy about it.
A charge of threatening behaviour likely to cause violence - related to an incident where Simpson allegedly angrily told Mr Brown he had two hours to return property he alleged Mr Brown had - was dismissed because there was no evidence the behaviour was likely to cause violence.
A second charge of threatening behaviour likely to cause violence was amended to a charge of insulting language, which has a maximum penalty of a $1000 fine.
That charge arose from an incident where Simpson allegedly stared in an intimidating manner, then yelled at a visitor, a man of Chinese descent, to the Brown's house that "the Chinese are invading us" and to "get out you Chinese buggers".
The visitor, known as Max, said he was "quite shocked" by what Simpson said, and was afraid he feared for several hours Simpson would come over the road and attack him.
Senior Constable Blair Corlet, of Clinton, gave evidence Simpson told him he saw the man "hiding in the trees", but could not tell what nationality he was.
Simpson pleaded not guilty to the amended charge.
His lawyer, Carmen Jillett, said the defence would say, among other arguments, the Browns must have also been watching Simpson and his home, that he turned on the vehicle lights at night so his injured wife could see the path into the house and that various witnesses were mistaken about who had been standing at the window at times, as it was often his wife looking out and not him.
The hearing was adjourned after the police evidence was heard.
It will resume in the Balclutha District Court, sitting at Gore, on July 23.
