One man is dead and a man and a woman are recovering in hospital after a stabbing attack in Narromine, in the state's central west.
It's understood detectives are investigating whether a 47-year-old man attacked a couple in their house then went home and took his own life.
Police said they were first called to a house in Ellengerah Street yesterday about 10.30pm, where they found a 34-year-old woman whose throat had been cut and a 54-year-old man with stab wounds to his stomach.
A short time later police went to a second home around the corner in Manildra Street, where they found the 47-year-old man lying dead in a pool of blood.
The woman was taken to Dubbo Base Hospital and the man was taken to Narromine Hospital. Both were in a stable condition, police said.
Both homes are being examined by forensics officers.
Anyone with information about the matters is urged to contact Dubbo Police on 6883 1599 or Crime Stoppers on 1800 333 000
Email a friend