The apparent murder suicide happened on Camden Avenue in St. Albans. Both of the deceased worked for the NYPD.
The violent drama unfolded in broad daylight and in front of neighbors along the sidewalk just before 8 p.m Wednesday.
Authorities are trying to figure out what pushed Officer Sherlon Smikle to his breaking point, as well as where he got the gun used in the deadly attack.
Sources say the 33-year-old officer had his service weapon taken away a few weeks ago after a domestic dispute with his wife, who was a New York City school safety agent.
Police say Smikle was off duty when he fatally shot his 46-year-old wife down the block from their home. The 8-year veteran then went back into the couple's home and shot himself.
His wife was rushed to Queens General Hospital, where she died.
Neighbors watched the horrific event unfold.
"I just heard about four big booms," neighbor Germaine Grubbs said. I went to the back, and about 10 minutes later I saw about four police trucks come in."
Smikle had been assigned to the 83rd Precinct in Bushwick, Brooklyn, but he had be reassigned after the domestic dispute with his wife.