Husband Dead, Mother-In Law Critical After Domestic-Related Stabbing

A man is dead and his mother-in-law is fighting for her life after a horrific domestic-related stabbing in Sydney's north-west.   

Emergency services were confronted with a distressing scene when they arrived at the North Richmond home on Enfield Avenue just after 10:45 am on Monday.

Three people were found with stab wounds, including the man in his late 40's who died at the scene.

"There is nothing more tragic than coming into a family situation and someone is deceased as a result," Detective Superintendent Jim Stewart told reporters on Monday afternoon. 

"To say it was gruesome, horrific ... all those descriptive words. It was."

A man is dead and a woman critical after a domestic-related stabbing at North Richmond Image: 10 News First

The man's wife, aged in her 40s, was treated for minor injuries while her mother, in her late 60s, suffered a serious neck wound and was airlifted to Westmead Hospital in a critical condition.

Det Spt Stewart said two 13-year-old girls -- one who is the pair's daughter -- were at the home at the time, but weren't harmed.

"They seem to be physically well, but there are a lot of other things happening and we need to speak to them," he said. 

"Their welfare is our priority and they're being looked after by family and carers."

Investigators are at the scene. Image: 10 News First

Police are yet to establish a motive but said the family was known to them for other domestic incidents.

Neighbours told 10 News First police were often at the home responding to loud arguments.

"When things like this happen, it just brings home how important it is to look after each other," Det Spt Stewart said.

"It’s unacceptable, particularly these days with what we try to do to make sure people stay safe in their homes."

Investigators remain at the scene.

If you or someone you know is in immediate danger, dial 000. If you need help and advice, call 1800Respect on 1800 737 732, or Lifeline on 13 11 14.

A range of domestic and family violence resources based around the country can be found here