Infatuated former work colleague could be involved in Melbourne woman's alleged murder

A man remains under police guard in hospital as police continue to probe the alleged murder of a young woman found dead in her Melbourne home.

Celeste Manno, 23, was found dead inside the house she shared with her mother on Umbria Road, Mernda, about 4.10am yesterday.

A 35-year-old man has been arrested in connection with Ms Manno's death.

Police are investigating whether the man is a former work colleague of Ms Manno who developed an infatuation for her.

Ms Manno worked at call centre in Mill Park.

CCTV shows a dark coloured Peugeot leaving the street after Ms Manno is believed to have been killed.

The same car crashed into the Mernda Police Station car park a short time later.

Blood stains remain on a fence beside the home where friends and family gathered today to mourn the music lover and cheerleading fan who was only weeks away from celebrating her birthday.

Ms Manno had a degree in criminology and psychology and spent much of her spare time after university doing volunteer work and working at the call centre.

Dozens of family members gathered in grief at the scene of the crime yesterday, with floral tributes continuing to grow outside the victim's home today.

Ms Manno's mother yesterday could be heard screaming: "How could I not protect her?"

Several other friends and loved ones posted tributes online.

"Celeste Manno was the most kind, brightest, down to earth person, who I was lucky to call a friend. She always knew how to light up a room with her bubbly, sweet nature," a friend posted online.

"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.

A crime scene was established at the Mernda home, along with the police station.

Anyone who witnessed the incident or with information is urged to contact Crime Stoppers on 1800 333 000.