Could be. What strikes me as odd is stabbing people to death is a loud and slow-ish method of killing unless you’re slicing jugulars, femorals, etc., which may have happened. All four found in bed, right? Maybe killer moved bodies or executed 4 jugular cuts on sleeping people 1 by 1. Jug cut is several seconds until lights out. Massive exsanguination and spray, even on a low HR sleeper. But why the chest stabs then?
Left hand over mouth...heart stab, liver stab, jugular slice.
Fastest is brain stem stab and twist.
Also, no clue what they did that night, but if you get pretty drunk, come home and take a couple bong hits you’ll be out.