State Police say it started around 9:30 Sunday night, with an argument between 50-year-old Anthony Campis and 47-year-old Lois Galasso.
They were inside a house on the 21-hundred block of Bustard Road in Worcester Township.
Police say during the argument, Galasso shot Campisi in the arm and abdomen.
Campisi managed to call 911.
When troopers got to the house, they say Galasso was still holding a handgun.
Investigators say she pointed the gun briefly at officers, then turned the weapon on herself and fired.
Galasso was pronounced dead at the scene.
Campisi is in guarded condition at the Hospital of the University of Pennsylvania.