Douglas County Sheriff Chris Degase say authorities got a 911 call from the Ava home about 1:30 a.m. Monday.
Authorities aren’t saying how the woman and child died, but they say the case is definitely a homicide.
Reportedly, family members told the Springfield News Leader that 24-year-old Mary Andrews and her 8-month-old son Tyler were stabbed to death by Dan Andrews, 33, who was the husband and father of victims. Family members also say Mary Andrews was pregnant.
The News Leader reports that Dan Andrews family says he has a history of mental illness.
Degase said when he arrived at the scene, the husband and father was outside the home but tried to run. The man was arrested and has refused to talk to authorities.
An autopsy is scheduled for this afternoon in Springfield.
A third resident of the home is who called 911 — that person is not considered to be a suspect.