Philadelphia police said Wednesday that a family of four, including a couple and two boys, were found fatally shot in their home Wednesday and the woman's 29-year-old son was in custody.

Investigators said officers were called to the home on Walton Avenue in West Philadelphia on Wednesday afternoon after the couple's employer had notified police that they did not show up for work, which was out of character for them.

BODY OF KIDNAPPED PENNSYLVANIA GIRL, 2, IS FOUND IN PARK, OFFICIALS SAY

They worked at a nursing home in Northeast Philadelphia, according to Fox 29.

When officers arrived, they found 51-year-old Janet Woodson's body by the front door, 18-year-old Sy-eed Woodson's body in a second floor bedroom, 7-year-old Leslie Woodson shot in the kitchen and 56-year-old Leslie Holmes in the dining room, police said. All four were pronounced dead on scene, according to investigators.

Arriving officers found a 29-year-old man, who police said is Woodson's son and Holmes' stepson, in a second-floor bedroom and took him into custody. A weapon was also recovered. Police said the family was known to have had trouble with a "mentally unstable son."

PENNSYLVANIA MAN IN COMA AFTER ASSAULT OUTSIDE PHILADELPHIA BAR, FAMILY SAYS

Philadelphia Police Deputy Commissioner Joe Sullivan told reporters a sergeant who showed up to the home noticed a car parked in front of the house and saw the trash had not been taken out, which he thought was “odd” given it was trash day. The sergeant then called the fire department for assistance, Sullivan added.

Officers were able to get inside the home from the second floor using the fire department’s ladder truck.

CLICK HERE FOR THE FOX NEWS APP

The investigation is ongoing.

The Associated Press contributed to this report.