The incident happened around 8:00 p.m. at on the 200 block of Wood Street.
Police say it involved all residents of the house.
Police say 41-year-old Michael Cahill stabbed his mother, 65-year-old Meredith Cahill, and fatally stabbed her boyfriend, 63-year-old Kenneth Robinson.
Meredith Cahill is listed in critical condition at the Jersey Shore Regional Medical Center in Neptune City.
Michael Cahill is in custody facing numerous charges.
Police are continuing the investigation.