A man has died after he was found with stab wounds to his chest and head.
Officers found the 57-year-old man at a house in Burdock Close, in Wymondham, Norfolk, at 23:50 GMT, but he died later in hospital.
A woman in her 60s has been arrested in connection with the death and the house remains cordoned off.
Det Supt Kate Thacker, of Norfolk Constabulary, said a murder inquiry had begun but it was thought "all those involved were known to each other".
Witnesses have been asked to contact police with information, but officers say they are not looking for anyone else in connection with the man's death at this time.