Probably early-mid ’70s anthology horror T.V. movie/special, not part of a series, which means it could be ABC.
Male child killer, possible family member, kills child, and then in the mansion where it took place, is tormented seemingly by the dead child.
At the end, child killer is on long winding stairs leading to ground floor, at wits end. I’m not sure who says this, but he is told that the dead child couldn’t be here, but he sent us to etc, etc. Screams, black out.
Scared the shit out of me. Don’t remember anything about the rest of the anthology, but I think there may have total three stories. But I was too traumatized to remember the other two parts!
— Ken J.
UNK SEZ: My bet Ken J. is that you were rightfully terrified by the last segment of DAN CURTIS‘ 1977 anthology DEAD OF NIGHT entitled “Bobby.” Check out the clip below and my review from long ago HERE! Wow, I just watched the scene again myself and it just never stops being scary does it? BTW, “Bobby” was remade by CURTIS in 1996 and appeared as the second segment of TRILOGY OF TERROR 2!