Butterfly fingernails used to pin child with murder

Statue of Lady Justice (file image)
Details of a bloody crime scene were aired in court as a 12-year-old girl faces a murder charge. -AAP Image

Pink butterfly fingernails found next to the blood-soaked body of a woman stabbed to death is key evidence prosecutors hope to use to convict a child of murder.

The 12-year-old girl, who cannot be named for legal reasons, is accused of fatally stabbing a 37-year-old woman at an apartment in Melbourne's inner west on November 16, 2023.

The child has been charged with murder and the onus is on prosecutors to prove she is capable of being held criminally responsible due to her young age.

Details of a bloody crime scene were aired in a Children's Court on Tuesday, as prosecutors sought an application to extract DNA from the girl.

"There was blood all the way from the kitchen floor into the bathroom and all over the bathroom floor," a homicide detective told the court.

"There was a substantial amount of blood on the floor in the kitchen and what appears to be drag marks in blood from the kitchen that leads into the bathroom."

She said when police arrived at the Footscray apartment, they found two neighbours and a girl in the hallway.

The neighbours had called triple zero after being woken up about 1.30am by a noise and finding a young girl crying in the hallway.

The girl told one of the neighbours the woman had killed herself, and "I tried to drag her into the shower", the detective said.

The neighbours entered the apartment and found the woman's lifeless body, naked and covered in stab wounds, on the bathroom floor, she said.

She said a knife was found in the victim's hand, with a pair of bloodied white sneakers next to the body.

The detective said crime scene examiners found a false fingernail, painted light pink with butterflies, bundled up with the woman's body after they removed her from the crime scene.

The child was seen on CCTV trying to steal alcohol from a nearby bottle shop, in the hours before the alleged murder, wearing the same false nails and in different clothing to what she was found in by police, she said.

The 12-year-old was also found to be carrying a bag holding four packets of false nails and two mobile phones, including one belonging to the victim which had selfies of the girl on it.

The nails, white shoes and knife, along with condoms, deodorant cans and clothing, including underwear, were seized by police.

Prosecutors are waiting for a forensic pathology report to come back on all items, but they want a magistrate to allow them to take DNA from the girl to match against the fingernails and shoes.

"There is no indication the deceased was wearing such fingernails," a prosecutor told the court.

The magistrate flagged issues around the child's mental capacity to consent to giving DNA due her intellectual disability, and because she is estimated to have the maturity of someone half her age.

He will decide whether to allow prosecutors permission to compel the girl to hand over a forensic sample at a hearing in March.

The girl remains in a secure welfare facility, after being granted bail there at the end of 2023.