By Kim Glovas and Diana Rocco

MEDIA, Pa. (CBS) — A Delaware County woman and her boyfriend are being charged with murder in connection with the beating death of the woman’s two-year-old son.

The District Attorney’s office has charged Shannon Matthews, 30, of Chester, and Daniel Grafton, 31, of Wallingford with third-degree murder and related crimes.

“It broke my heart broke my heart, real sad for me,” says a neighbor.

This woman lived next door Matthews and her two kids, a six-year-old and two-year-old Mason for several years.

She didn’t want to give her name, or show her face, but says she heard screaming on a nightly basis and often called the police, the last time just days before Mason’s death after he was doused in seasoning salt.

“She’d call him some foul filthy names and say I’m going to kill you.”

Officials say two-year-old Mason Hunt had been beaten and pinched, at least 120 times, on the head, body, and in the groin.  The DA called it “a particularly horrific case where a two-year-old boy is senselessly beaten and left for dead by his own mother and her boyfriend.”

Mason’s mother worked in the doctor’s office below her Norwood apartment. On February 3, Grafton brought Mason downstairs in a blanket and said he had stopped breathing in the tub, but when first responders arrived his body was cold and his bruises were evident.

Investigators say Mathews and Grafton had been hiding Mason in the apartment for days to cover his massive injuries.

Knowing now, this woman who lived just a door away wishes she could have done more.

“I wished I had known because I see myself bending down and picking him up.”

The Department of Child and Youth Services had been checking in on this family, the last time the day before Mason’s death.

Both Matthews and Grafton were being held without bail in the county prison.