Tiny detail in photo debuting murdered student's new romance 'sent her accused stalker into an alleged stabbing frenzy' - as her 'obsessed' ex-coworker is pictured for the first time

The family of a student who was killed in her bed believe a picture of her touching her boyfriend pushed an alleged stalker over the edge and into a stabbing frenzy.

Melbourne woman Celeste Manno, 23, was found dead in a home at Mernda, to the city's northeast, at about bout 4.10am on Monday.

Suspect Luay Sako, 35, is under police guard in hospital after handing himself in following her death. 

In an emotional tribute, Ms Manno's brother Alessandro shared his disappointment that he was unable to protect the 'beautiful' and 'loving' young woman.  

Ms Manno's family think a picture of the 23-year-old and boyfriend Chris Ridsdale linking arms likely triggered the alleged attack. 

Celeste Manno's family think this picture of the young woman and her boyfriend Chris Ridsdale linking arms likely triggered the alleged attack

Pictured: Suspect Luay Sako, 35, is under police guard in hospital after handing himself in following her death

She shared the photo to social media on Saturday night and it was the first time she posted with a man since the alleged harassment begun, The Herald Sun reported. 

Her 19-year-old brother Alessandro said: 'It was like if he couldn't have her, no one could.'  

Alessandro remembered his sister in a Facebook post on Wednesday. 

'I am in tears writing this right now and there is never gonna be a perfect way to say this, but to my beautiful and amazing loving caring sister Celeste, you were my everything,' he wrote.

'You were my sister, best friend, and most importantly the most amazing beautiful person in my life and I can't believe your gone and I can't hug you and can't kiss you every day after work.

'I need you so much Celeste and I need you to help us all get though this cause I can't do this by myself, I need you, mum needs you and all of our family needs you.'

Alessandro described his sister's alleged killer as 'cowardly'. 

'He chose the one night in my life I was away from home for the night and couldn't been there to protect you like you always did for me,' he wrote.

Ms Manno was studying at university and worked at a Serco call centre

On Wednesday, Alessandro paid tribute to his sister in an emotional Facebook post. The siblings are pictured together

Alessandro described his sister's alleged killer as 'cowardly'. 'He chose the one night in my life I was away from home for the night and couldn't been there to protect you like you always did for me,' he wrote

The Facebook tribute included numerous pictures of the siblings during happier times. 

Ms Manno's devastated family faced the media outside their home on Tuesday and revealed the alleged killer was comforted by the young woman when he was fired 18 months ago. 

Her father Tony was accompanied by sons Jayden and Alessandro and uncle Gabriel outside the family home where they described the alleged killer as 'evil'. 

'She wasn't close with him at all, but just to give him some support she walked him out the door,' her brother Alessandro said, who refused to name him. 

'Ever since that day he has been obsessed with her and harassing her over social media for months and months with like vulgar and disgusting messages.' 

Alessandro (pictured with Ms Manno) said his sister was 'the most amazing beautiful person in my life'

The Facebook tribute included numerous pictures of the siblings during happier times

Ms Manno was employed at a Serco call centre and it's understood Sako previously worked in her team. 

In March, the terrified woman was forced to file an intervention order against her alleged tormentor.

He disappeared that month, but the messages eventually started up again.

Tony Manno said the justice system had let his daughter down.

'It let my daughter down,' he said. 'And it's gotta be changed. It won't bring her back but it has to be changed.'

Jayden , Alesandro, Gabriel and Tony Manno, with baby Daisy, outside the home where Celeste Manno was killed on Monday

About a dozen friends joined Ms Manno's boyfriend in a footpath vigil to mark the awful tragedy

The abuse started about January where the alleged offender would bombard Ms Manno over Instagram.

'At first she would be nice to him and just say 'look thank you but I'm not interested',' Alessandro said.

'Then he became obsessive so eventually she had to block him and he created about a million other accounts until this happened. I hope justice gets served to him in more ways than one. I hope he rots.'

Alessandro said he had never gone more than two days apart from his sister in his entire life.

On the night she was killed, he had spent a rare evening away from the home.

'It was actually my first night away from home in my life. My first night ever in 19 years and it was the one night this happened. So I can only assume he planned it,' he said.  

'I feel like she's going to come home from work any minute ... I don't know how we're going to get through it.'

A mourner laid a bouquet of flowers and cried out the front of Ms Manno's home on Monday

Ms Manno's boyfriend, Chris Ridsdale, was embraced by friends out the front of her family home in Melbourne's north on Tuesday afternoon

Celeste Manno's father Tony cradles baby Daisy and begs the Victorian justice system to change 

The family remain unsure how Ms Manno's killer found out where she lived. 

'He must have been stalking us,' Alessandro said. 

The men paid tribute to Ms Manno, describing her love for her niece Daisy, whom was cradled by her father Tony. 

'Celeste adored her. She was absolutely in love with her niece,' Tony said.

'Celeste was coming over tomorrow night to visit after COVID. COVID kept us all separated too long and little Daisy was really looking forward to seeing her.' 

The family described their loved one's killer as 'evil'. 

'It's harrowing. Such a senseless and unfathomable evil act,' Jayden said. 

'It should never have happened to our family, not to anyone's family. Evil. This can't happen.'

Jayden said everyone had the right to live their lives in the safety of their own home. 

'No-one should be scared - man, woman, child. No-one,' he said. 'This evil should not exist. Things need to change. This evil cannot be allowed to continue.'

It is understood the Sako remains in a Melbourne hospital under police guard after sustaining minor injuries. 

He is believed to have forced his way into Ms Manno's property by smashing a window at the rear of the house.  

Victoria Police established two crime scenes - one at the home and another outside the police station where the 35-year-old man is believed to have driven to 

It is not known how the killer got inside and homicide detectives are still working to determine the circumstances surrounding Ms Manno's death

Ms Manno's boyfriend arrived outside the Mernda property at about 2.30pm on Tuesday and was embraced by the alleged victim's friends.

Mr Ridsdale tearfully placed a bouquet of flowers and a photo of the couple beside a tree that has become a makeshift shrine. 

The pair were supposed to celebrate Ms Manno's birthday this week, and had been excited about spending Christmas together.

Instead, a devastated Mr Ridsdale was forced to mourn beside the footpath outside the home where the university graduate and Serco worker was killed on Monday morning.

Up to a dozen of Ms Manno's friends joined him at the site while a glazier worked to repair a large glass panel within the property.  

Ms Manno, 23, was found dead in a home at Mernda, to the city's northeast, at about bout 4.10am on Monday 

Forensics officers placed evidence markers next to bloodstains on the front fence of the home

In a powerful post, Mr Ridsdale's sister, Sarah, wrote on Facebook that Ms Manno 'wasn't even safe in her own bed'.

' was supposed to be celebrating her birthday with Chris this week,' Ms Ridsdale said.

'She was supposed to be having Christmas with our family. Her family. Her mother. Her brothers.'

In a message that quickly went viral, Ms Ridsdale said: 'I sit here watching my younger brother shake with tears. I can't do anything.

'We need our legal system to get off their arses and start taking this seriously. Stalking is a sign of things to come.

'She wasn't even safe in her own bed. If the law had done something about this ages ago, she may still be here.'     

Tributes poured in online for the young woman, who was remembered by friends as a 'beautiful soul'.  

Ms Manno's mother tried to run through the crime tape as her daughter's body was removed from the house but was stopped by officers

A masked man leaves flowers out the front of the property this week 

'Fly High Beautiful girl,' her friend Maddi Jonhnston wrote on Facebook.

'The most loving, generous and kind hearted friend to everyone around her... You will be missed. I will forever cherish the memories that we made and for the friendship that we gained.

'This world can be cruel, and you did not deserve this at all.'

Friend Loretta Cimini said: 'She was always selfless and always put everyone else first before herself. 

'She was an absolute angel who didn't deserve a tragic ending like this! The world has truly lost a ray of sunshine today.' 

Another mate, Bertine Rashou, said Ms Manno was' the most beautiful soul' she had ever encountered. 

'I am absolutely shocked and devastated. I have no words my heart is broken,' Ms Rashou said.  

Ms Manno joins a string of women who have been viciously murdered by male stalkers in Melbourne.

In 2019, Aiia Maasarwe was on her way home in Melbourne in January 2019 when she was followed, raped and murdered by Codey Herrmann after getting off a tram in Bundoora.

A year earlier, 22-year-old Eurydice Dixon was stalked for more than an hour before being raped and murdered in Carlton North's Princes Park by a stranger.

If you need help in a crisis, call Lifeline on 13 11 14. If you or someone you know is affected by domestic violence, contact 1800RESPECT. 

WOMEN WHO HAVE BEEN STALKED AND KILLED IN MELBOURNE

Pictured: Jill Meagher

Jill Meagher: Ms Meagher was 29 when she was raped and murdered in Melbourne by serial sex offender Adrian Bayley, who stalked her on the way home from a pub on September 21, 2012.

Her case was initially treated as a missing person after she failed to return home to her husband, but her body was discovered by Victorian police six days later. 

Bayley is serving a life sentence in prison, with a non-parole period of 35 years. 

Pictured: Yuk Ling Lau

Yuk Ling Lau: Ms Lau was 32 and walking to work when she was followed, beaten unconscious and raped near the police memorial in the King's Domain Gardens in June 2014.

Homeless man Scott Miller was eventually captured and sentenced to 33 years in prison with a minimum term of 28 years over Ms Lau's murder. 

Masa Vukotic: In 2015, 17-year old Masa Vukotic had been at school and eaten dinner with her family before she decided to go for a walk.

Pictured: Masa Vukotic

Sean Christian Price saw her and instantly decided to kill her. 'I just f**king had to kill her, man. I f**king had to kill her,' Price told police.

Price took the the knife from a bag he was carrying and ran up to her. He pushed her into the bushes where she pleaded with Price not to hurt her. Masa told Price she would do anything he wanted her to do. Price ignored her and began stabbing. 

Eurydice Dixon: In 2018, the 22-year-old was stalked for more than an hour and raped and murdered in Carlton North's Princes Park by a stranger later identified as Jaymes Todd, 19.

Pictured: Eurydice Dixon

She had spent the night performing in a comedy club and was walking home after her performance. 

Todd was sentenced to life behind bars with a non parole period of 35 years - a sentence which he argued was 'manifestly excessive' due to his youth and previously clean record.

Aiia Maasarwe: Ms Maasarwe was on her way home in Melbourne in January 2019 when she was raped and murdered by Codey Herrmann after getting off a tram in Bundoora.

Pictured: Aiia Maasarwe

Herrmann repeatedly beat Ms Maasarwe over the head with a metal pole and sexually assaulted her, before covering her body in flammable WD-40 spray and setting her alight. He was sentenced to 36 years in jail.