Medics were called to a home in the Presidential Lakes development off Route 70 in Pemberton Township at 7:00 a.m. Friday.
There they found a woman in her 80s who had suffered a gunshot wound to the chest.
She was pronounced dead a short time later.
A spokesman for the Burlington County Prosecutor's Office told Action News a preliminary investigation reveals that the wound was self-inflected.
Authorities say the woman had a developmentally disabled son, and that there was no indication of foul play at the scene.
An autopsy was scheduled to be performed on the victim.