When officers arrived, they found a man shot to death in the kitchen of the home on 6th Street.
He was taken to Good Samaritan Hospital where he was pronounced dead.
Apparently a woman and her boyfriend were inside the home when the woman's ex-husband came inside the home.
The couple said they assumed a burglar was breaking in and the boyfriend allegedly shot the man.
"It's an ongoing investigation. The deceased did not live at the house. The matter is under investigation at this time as to the circumstances of the shooting," said Detective Lieutenant Gerard Pelkofsky, Suffolk Police Homicide Squad.
The man was shot in the upper body according to investigators.