Ms Dalziel began giving evidence yesterday afternoon and said today she visited Ms Fan's house on November 8, 2013, and took mail from her letter box and placed it under the door.
She did not notice any blood on the door handle or surrounding areas.
Police Sergeant Daniel Hughes then told the court about Preston walking into the Wellington police station on October 21 and complaining about Ms Fan, alleging she had obtained a New Zealand driver's licence by using false identification documents.
Michael Preston is on trial for Ms Fan's murder in November 2013. Photo / Supplied
Preston said Ms Fan's uncle was a cop in China and had arranged the forged documents, which had an incorrect date of birth.
"Preston said it was commonplace in Chinese culture for woman to change their date of birth to make them seem younger," Mr Hughes said.
Preston said he wanted Ms Fan investigated and charged.
On November 10, 2013, Mr Hughes attended the crime scene at Ms Fan's Brussels St house.
That evening Mr Hughes received an email from Preston about the fraud complaint.
He subsequently went to Preston's house and told him about a serious incident at Ms Fan's house.
Mr Hughes told Preston he would need to search him and his house. Preston and Ms Fan's two children were there.
"The accused did not appear to be shocked that there were a number of armed police officers at the address. He seemed to be more mildly perplexed," Mr Hughes said.
Another officer arrested Preston.
"On hearing this, the accused said he felt like he couldn't stand. He appeared to lose control of his legs."
Constable Olliver Crellin was also present when Preston was arrested.
He said while Preston was told of an incident at Ms Fan's house, nothing was said about her suffering harm.
But when told of the incident, Preston became "visibly upset".
After appearing to go weak at the knees, Preston sat on the door step, Mr Crellin said.
"He said a few things while he had his head down that were muffled. I couldn't hear them."
Mr Crellin said he and another constable were carrying rifles but this didn't appear to faze Preston.
Sergeant Caroline Marner, police family safety team supervisor, went through a lengthy list of complaints she received from both Ms Fan and Preston about each other.
In 2013 the situation between the two veered from Ms Fan wanting a trespass order to keep Preston off her property to the two appearing to be together.
