The Serious Incident Response Team (SiRT) is investigating after a 29-year-old man died while being taken into custody in Dartmouth, N.S., on Wednesday night. Halifax Regional Police responded to a report of a man threatening a woman known to him at a Hillsburn Court residence around 10:55 p.m. Officers then learned the man was assaulting another man at the location, according to a news release from police. A separate news release from SiRT says police received two 911 calls from a Dartmouth residence about a man who was “experiencing a mental health crisis and becoming violent.” Police say officers at the scene found the 29-year-old man being restrained by the other man. Police took him into custody, but found he was unresponsive. Officers removed the handcuffs and started life-saving measures, according to police. The man was pronounced dead at the scene. The other man went to hospital with what were believed to be non-life-threatening injuries. SiRT is responsible for investigating all matters involving death, serious injury, sexual assault and intimate partner violence that may have arisen from the actions of police officers in Nova Scotia and New Brunswick. For more Nova Scotia news, visit our dedicated provincial page