NORRISTOWN, Pa. (AP) — Two men tipped off through their junk hauling jobs about a gun cache at a suburban Philadelphia home broke into the wrong house and shot a woman in bed before killing her adult son earlier this month, prosecutors said.

Bernadette Gaudio, 61, who was bedridden from a medical condition, is now paralyzed after being shot several times, Montgomery County District Attorney Kevin Steele said at a press conference Tuesday. The woman's son, 25-year-old Andrew Gaudio, was shot in the back of the head as he tried to protect her, officials added.

“The motive in this case was to steal guns. And they simply got the wrong house,” Steele said.

Bernadette Gaudio was able to call 911 during the Dec. 8 attack at the Lower Merion home. The suspects left with a jewelry box and a Jeep, authorities said.

Detectives traced a vehicle one suspect drove to the scene to a Philadelphia home where they found the jewelry box, they said. At the other suspect's home, they found a 3D printer, tools used to make unregistered ghost guns and a 9mm ghost gun they believe was used to kill Andrew Gaudio.

The two co-workers are charged with first-degree murder and other crimes and are being held without bail.