A person of interest has been identified as their older son, 22-year-old Ryan Hanafin, who is the subject of a manhunt.
He has been described as 5 feet, 10 inches tall. The only photo of him released by police shows him with shoulder-length, straight blonde hair, a mustache and glasses.
The DA said there was "no significant history" of police calls to the family home.
Ryan Hanafin is believed to be driving a black 2010 Dodge Charger with the Massachusetts license plate 2PSY15.
The younger son was out with friends until around 9 p.m. and told police he went directly to his bedroom when he got home and did not see his mom, according to DA Ryan.
Matthew Hanafin told investigators he hadn't spoken with his older son since Wednesday morning, she said.
Reading Police Chief David J. Clark said that while Ryan Hanafin is a person of interest, he should still be considered "potentially armed and dangerous." Anyone who sees him or his vehicle is asked to call 911.
"By all means, please do not approach him," he said. "Please contact 911, the local police department, whatever, if you see the vehicle or come across him. We are urging people to stay safe and not put themselves in danger."
This is a developing story.