The update on the horrific story of a mother and three children being found dead in their home at Tullarmarine.As usual, the first suspect was the father, to the extent that he was HANDCUFFED and surrounded by SIX POLICE OFFICERS. Just imagine how he felt after discovering his wife, and his three children dead, to then be treated in such a disgusting way! (Eds comments)ANGELICA SNOWDEN REMY VARGA REBECCA URBAN

Tomislav and Katie Perinovic with children, from left, Claire, Anna and Matthew in a Christmas photo; below, forensic police at their home on Friday DAVID GERAGHTY

Mark Stephens and daughter Sienna lay a tribute at the Perinovics’ house in Tullamarine on Friday On Monday, as the mercury soared in Melbourne’s northwest, Daniel and Vicky Schembri were listening to the joyful squeals of the three young children next door playing in their pop-up swimming pool.

Mr Schembri was prepping his back door, which he was about to paint, when he heard them.

“They were yelling and screaming and having fun and all that,” he said.

Two weeks earlier, the children — Claire, 7, Anna, 5, and Matthew, 3 — had popped over with lollies to share on New Year’s Day. On Wednesday, their mother, Katie Perinovic, visited in the late afternoon to drop off some plums. “We were watching TV, she knocked on the door and said I have a bag of fruit for you, Daniel,” Mr Schembri said.

By Thursday, Mrs Perinovic, 42, and her three children would be dead, the subject of a police homicide investigation.

Her husband Tomislav, 48, who had been helping police with their inquiries after making a call to triple-0 about midday, was released without charge on Friday, confirming what many neighbours on the quiet street did not want to believe.

According to Victoria Police, homicide investigators had formed “the preliminary view” that Mrs Perinovic, 42, was responsible for all four deaths.

“On completion of their investigation, a report will be provided for consideration of the coroner,” police said.

“Victoria Police would like to thank everyone who assisted in this distressing and challenging investigation.”

Residents of the suburban neighbourhood in Tullamarine, a mixture of elderly couples and young families, were struggling to make sense of the tragedy.

Kevin and Clare Harrison, who live opposite the family, cried when they heard the news.

“We shared coffees, we have sat on their front veranda and just laughed at the kids and the way they just ran around in the yard,” Mr Harrison said.

“I used to talk to Tom while he was teaching Matthew how to ride a bike … everyone around here was involved with them because of the kids.

“Christmas Day, every year we have given the kids Christmas presents because we have known them from birth.”

This year was no different.

“We sat with them for a little while and Tom was on the floor playing with little Matthew with the cars that we gave him,” he said. “He was helping the girls unpack their bits and pieces. We were just laughing and joking about stuff.”

Mrs Perinovic only recently went back to work as a physiotherapist, said neighbour and friend Marie Groves.

“She only started working again really in the last year and a bit because of Matthew, she loved her kids and did everything for her kids,” Mrs Groves said.

“The last time we saw them was the end of November for my seven year-old’s birthday,” said Mrs Groves’ husband Steve .

Mrs Groves added: “She seemed a bit withdrawn, a bit quiet and that was the first time I had ever seen her that way.”

The Perinovics had lived on Burgess Street since the children were born. Claire attended nearby St Christopher’s Catholic School in Airport West, where younger sister Anna was due to start in a few weeks.

Principal Adrian Glasby said on Friday: “Claire was a kind, diligent, and much-loved student at St Christopher’s and we were looking forward to welcoming Anna, with her huge smile, into prep to begin her school journey in just a couple of weeks’ time.”

Parish priest Peter Hoang wrote to members of the community on Friday confirming the news “with deep sadness”. “As is being reported in the media … Katie Perinovic, her daughters Claire ... and Anna and son Matthew, aged 3, died tragically at the family home on Thursday,” Father Hoang wrote.

“We are deeply shocked to receive this news and extend our sincere sympathy and prayerful support to Tom, the Perinovic family and all those struggling to comprehend this sudden and tragic loss of life … As a Catholic, faith-filled community, we draw strength and solidarity from our Loving God at this sad and challenging time.

“May God’s grace be found in the kindness of those supporting the Perinovic family. May we also take some comfort in our faith that God’s arms are already welcoming Katie, Claire, Anna and Matthew to their eternal home.”

Mrs Perinovic had worked at the Glenroy Physiotherapy Centre in Melbourne’s northwest, about a 10-minute drive from her home, and studied at Melbourne University ›

Neighbours said Mr Perinovic was a mechanic, working at Ford.

He had lived with his sister at the Burgess Street property after he bought it in the late 1990s and then he met Katie.

“He was single and then one day he got a girlfriend and she came in and said ‘we are getting married’ and the next thing we knew she was pregnant,” Mr Schembri said.

According to the Schembris, when they saw Mrs Perinovic on Wednesday she had seemed to be her normal, friendly self.

But it became clear the next afternoon that the seemingly ordinary family next door had become embroiled in something unsettling.

“We came outside and saw Tom sitting down and the police said get inside and stay there (to Tom),” Mr Schembri said.

“He looked numb,” Mrs Schembri said.

She added that Mr Perinovic was handcuffed and surrounded by up to six police officers.

Across the road, Ms Harrison returned home from an appointment to find police cars and paramedics on the street.

“We couldn’t understand what was going on, then I looked at the house and said ‘that’s Tom’,” Ms Harrison said. “We are in a state of shock. There is nothing that could describe how it is.”

The Harrisons described the Perinovic family as “the friendliest, loveliest people” and said they may never get over the incident.If you or anyone you know needs help, call Lifeline 13 11 14.