Suffolk County police say Southampton Town police shot and killed a man armed with a knife Sunday afternoon while responding to an escalating domestic situation in Riverhead.
Detectives say officers responded to the scene on Topping Drive at 2:40 p.m.
A woman was taken to the hospital with serious injuries.
Three Southampton Town police officers were treated and released at the hospital, according to Suffolk County police.
The circumstances of the incident were not immediately clear as of Sunday night.
Suffolk County police said detectives from the New York State Attorney Generals Office responded.