This post has been updated.

A woman walked into her sister's North Philadelphia home late Tuesday night and made a ghastly find, cops said: her 52-year-old sister slumped on the couch, dead of severe blunt-force head trauma.

Medics arrived at the scene, in the living room of a rowhouse on Gratz Street near Susquehanna Avenue, and pronounced the woman dead at 10:50 p.m. They were unsure how long she'd been dead, but relatives told investigators they'd last seen the woman around 8 p.m.

Police said there was no sign of forced entry into the house and were unsure if anyone else lived there with the woman. Police found a weapon they believe was used in the murder inside the house early Wednesday morning.

Police and homicide detectives were still at the scene investigating Wednesday morning, and some of the woman's relatives had been taken to Police Headquarters to speak with investigators.