A woman has been charged with murder after a baby was found stabbed to death inside a Perth home.

A serious assault at a house on Campion Ave in Balcatta was reported to authorities about 3am on Monday.

WATCH THE VIDEO ABOVE: Baby found dead in Balcatta home.

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The six-month-old boy was found with critical injuries and was declared dead at the scene.

The boy’s mother, a 31-year-old Balcatta woman, was taken to Sir Charles Gairdner Hospital under priority conditions.

It is understood she had no physical injuries but was taken to hospital for a mental health assessment.

She has been charged with murder and is due to appear in Perth Magistrates Court on Wednesday.

Police said that at the time of the incident, the woman was present along with a man and a young person.

When asked if the woman was the baby’s mother, WA Police Commissioner Col Blanch confirmed “she is”.

7NEWS understands the woman’s 13-year-old daughter called triple-0 after making the horrific discovery.

Blanch said the incident is being treated as a domestic violence homicide.

“We believe it’s confined to the family and will be treated as a domestic violence homicide,” he said.

He described the scene as distressing for emergency crews.

“There would be very few cases where you would have a crime scene of such a horrific nature for our officers and all first responders involved.”

If you or someone you know is impacted by sexual assault, domestic or family violence, call 1800RESPECT on 1800 737 732 or visit 1800RESPECT.org.au.

In an emergency, call 000.