Police say a body-worn duress alarm saved the life of the 92-year-old Sydney woman, who was allegedly stabbed multiple times by a cleaner who had been in her employ for about a year.
"For elderly people, and others who may live on their own, what a valuable device this is. Not only if people have a fall," NSW Police Force Superintendent David Johnson told media on Thursday.
"Or if there is an intruder or any other incident where they require assistance, they can activate these duress alarms and they will get help in a very short period of time. And I'm sure that device assisted to save that victim's life."
Superintendent Johnson described the incident as a "vicious attack", with police discovering the woman bleeding heavily from her scalp and abdomen, police said.
Emergency services arrived at an address on Holden St, Ashbury within moments of the alarm being sounded at around 10.45am on Wednesday.
"When they attended the scene they were confronted with an elderly victim who had been viciously attacked in her home," Superintendent Johnson said.
"Police were quick to assist the victim. And the victim was conscious at the time and were able to provide police with certain information."
That information led to the arrest of a 35-year-old woman after a vehicle stop on Griffin Parade, Illawong on Wednesday.
She was taken to Sutherland Hospital for an ankle injury and was due to appear at Parramatta Bail Court on Thursday, charged with attempted murder and wound person with intent to cause grievous bodily harm.
Police said the 92-year-old is in an induced coma in a serious condition at Royal Prince Alfred Hospital and will require further surgery.
Police said at this stage the motive is unclear.
