Today, Detective Constable Jacquiline Taggart said when they finally caught up with Slater to get a statement she appeared to be high on a "narcotic" and her behaviour "erratic".
"She was just like, verbal diarrhoea like she had to get it out."
She said Slater was anxious about giving a statement as she was concerned for her safety.
"She didn't feel safe to do a statement at [her home] because, she says, 'everybody knows when you pigs are here'. People see the cars coming and going and it just makes her life hell, so we agreed to go to a mutual location … a motel."
In her evidence yesterday, Slater said she and Swinton had broken up around the time of the death and remained that way for several months.
The couple had since had a third baby, which was now one month old.
Taggart said a protection order was still in place on Swinton in regards to Slater, and had been in effect since September 21, 2016.
Police had been called to 17 domestic violence incidents between the couple over the past couple of years. One of the assaults on Slater by Swinton involved him assaulting her with a baby bottle.
She said that Slater was polite and reasonable when she was by herself, but when Swinton was around she became "more aggressive".
Defence counsel Jonathan Temm put to her examples of times when Slater's behaviour was erratic when his client was in custody, and attempted to dismiss the suggestion it changed when he was around.
However, Taggart maintained her position.
"I think a lot to do with her demeanour is her fear of what Henare Swinton will do to her and that shows in the high family violence [incidents] between the two of them."
Meanwhile, a police witness was taken into custody after refusing to answer questions and attempting to storm out of the courtroom partway through giving his evidence.
Karaitiana Waenga-Matthews told the court he was in the area for his uncle's unveiling, recalled seeing the Odyssey earlier in the day and then went and started drinking at the nearby Mongrel Mob gang pad.
However, when pressed more about names of the gang members, Waenga-Matthews began abusing Crown prosecutor Anna Pollett and tried to walk out of the court room.
"I'm saying that I'm f****** sick of this shit, that's what I'm saying. I don't give a f*** anymore, eh. I want to go home and go to sleep, I've been up for 24 hours."
However, when informed by the judge he would be put in the cells, he came back.
After getting legal advice, Waenga-Matthews eventually finished his evidence and was allowed to go home.
The trial continues.