South Australian police are investigating a fatal stabbing that has left an 81-year-old man dead and a 78-year-old woman with serious injuries.
Police were called to the house at McLaren Vale south of Adelaide just before 7pm on Tuesday after reports of a serious assault.
They found the 81-year-old man dead at the scene and the woman with serious injuries.
The woman was taken to Flinders Medical Centre in a serious condition.
A 22-year-old man known to the couple was detained by police at the home and later arrested and charged with murder and attempted murder.
He has been refused bail and will appear in the Adelaide Magistrates Court on Wednesday.
Police do not consider the incident to be random, as all three people are known to each other.
Major Crime officers have attended the scene to assist Southern District CIB detectives with the investigation.
Police are calling for anyone with further information to contact Crime Stoppers.