The Herald can reveal that on Tuesday, the 38-year-old community-based patient under supervision by the Auckland District Health Board had been asked to move out of the property after his flatmate complained to their landlord about his "odd behaviour".
But the next day, his flatmate - who the man met a week earlier - was found dead inside the Balmoral Rd house.
The accused, who health authorities considered stable and was living in the community after a range of assessments, was arrested yesterday, an hour after police were called.
It is understood the man socialised with a group of fellow mental health patients. A few among the group had recently died, including one man who lost his life after falling under a suburban train.
A witness said the accused man had tried to push his way into a neighbour's unit about 1.20am Tuesday morning.
David Hogg, who was visiting at the time, said he was asking for a girl who didn't live there.
"He kept asking if Katie lived here, it was really weird. He tried to push his arm through the door but we closed it."
Later that day, Mr Hogg saw the man lying in the rain on the concrete outside his unit.
Asked if he was okay, the man raised his hand in the air.
The neighbours stayed elsewhere on Tuesday night as they were worried he would come back.
The victim called his landlord that day saying he was concerned about his new flatmate's "odd" behaviour and wanted him out of the house.
"My tenant decided it would be a good idea to get a flatmate," the landlord said.
"He wasn't using one of the rooms, so five days ago he met this guy and said 'why don't you stay here?'
"He's a really genuine guy ... [the accused] had no where to go. Five days later, [the victim] is dead. He didn't deserve that."
The landlord, who did not want to be named, said neighbours had seen the accused walking around the street talking to himself. They told him he also yelled out to women walking past the house and "hit on them".
He said he spoke to the victim after the neighbours complained.
"He told me he'd been trying to get rid of the flatmate because he wasn't suitable, but he couldn't get him out of the house."
The landlord gave the victim a notice asking the accused to move out, and giving him 10 days notice.
Soon after, the accused man confronted the landlord.
"I was doing some work at the house and he came out. He said 'so you're the landlord', in a bit of an aggressive way. He was shaking a bit and I calmed the situation down and told him I was responsible for the property.
"After that, he said to me, 'I'll be out by lunchtime tomorrow'. He was right, that's when I got the call about the murder.
"I expected him to be angry at me, I didn't expect him to be angry at [the victim]. I thought that the note would take the heat off my tenant."
The landlord said it was obvious the man had mental health issues. But, as he had done nothing to harm or endanger himself or anyone else, or committed a crime, it would be pointless alerting police or other authorities.
"If I knew of some place to call to get him picked up and get him some help, I would have called that number. If I thought police could have done anything last night, I would have rung.
"I didn't realise how serious the situation was ... that's devastating. As a landlord you try to keep people safe, you try to do your best to make sure they are looked after. This is the worst possible scenario, I feel responsible for it. I do, I feel responsible."
The Sensible Sentencing Trust's mental health issues spokesman, Graeme Moyle, urged the health board to be open with the community about issues involving patients it was treating in the community.
Police spokeswoman Noreen Hegarty said the victim's family were still being notified.
She said scene examination was expected to continue for some days.
"It's unclear how well the two men knew each other but both were residents at the address, one more recently than the other," she said.
