Authorities have said that three men were found shot to death, execution-style, in a Northeast Philadelphia home over the weekend.

The Associated Press reported that officers responded to the home around 11:30 p.m. Saturday after the girlfriend of one of the victims went to the house and discovered the grisly scene.

The woman got inside through an unlocked back door and found each of the men fatally shot in a first-floor apartment of the city’s Mayfair section.

"She had to turn the knob, she walked in, and found one male victim on the kitchen floor and she walked in to see her boyfriend on the couch and another unknown male," Philadelphia Police Inspector George Fuchs said.

On Monday, WPVI noted that police released the identities of the victims. They are Ramon Ortiz, 40, Sarith Mang, 30 and 40-year-old Jason Stratos.

Police have not yet released a possible motive for the killings, but some neighbors told local news outlets that they believe there was drug activity going on at the residence.

One news station reported that a sign on the apartment door read "Trespassers will be shot. Survivors will be shot again."