A man has died after police fired a Taser at him at a property in Wiltshire.
Police said it happened in Warminster late on Wednesday night, when officers responded to a report of a man who had harmed himself and was threatening to harm others.
The 44-year-old man died at the scene.
The matter has been referred to the Independent Police Complaints Commission (IPCC), which has launched an investigation.
The IPCC said it was examining contact between police and the man before his death.
It said officers entered the address where they came into contact with the man, who has not been formally identified.
A spokesman said initial reports indicated he had caused himself serious harm and a knife was recovered from the scene.
An ambulance was called but the man was pronounced dead at the scene at about 00:30 BST on Thursday.
Assistant Chief Constable Paul Mills of Wiltshire Police said that due to the IPCC inquiry it would not be appropriate for the force to make further comment.