A Sydney woman murdered in Penrith was a mother of two in a new relationship.
A man was arrested after she was found dead in a western Sydney unit on Monday afternoon.
Domestic violence journalist and campaigner Sherele Moody identified the woman as 28-year-old Dayna Isaac.
"Dayna was a mum to two daughters," Ms Moody said.
"She had known the man suspected of killing her for quite a while but their friendship only became a relationship in the past couple of months."
Her burned out car was found in bushland nearby and is being examined.
Police were informed by a relative of the murdered woman.
The NSW Police tactical operations unit arrested a 32-year-old man at a house five kilometres away in Cranebrook on Tuesday morning.
"We are aware that there was a relationship between the two," acting superintendent Carlene Mahoney told reporters on Tuesday.
"It was a long relationship as a friendship and recently become more intimate over the last couple of months and that's as far as we're aware."
The man is in custody at Penrith police station.
Supt Mahoney added he had prior domestic violence incidents recorded.