the molten metal object is interesting. I thought if there was a ceiling fixture or a handle or decoration on the
amoire maybe that's what melted. But zinc is would splash if dripped from above. If the pre-melted object was on the floor,
the accelerant (gasoline) would actually be a cool spot (relatively) because of the evaporating fuel, with the area above it being very hot.
There are replica knives and also letter openers made from zinc (not many), but they would make poor weapon because
zinc breaks easily, and anyway, they wouldn't be very sharp or pointy.
But a utility knife could fit the puzzle nicely. (could -- not saying this happened)
a utility knife is usually zinc, they weigh an average close to the weight of the found metal (about a third of a pound)
are coincidentally the same size as the metal 2 inches by 6 inches and are not made from pure metal, so copper and
aluminum would be likely
i don't have a supply of test knives or a good place to set a floor on fire, but i believe if you soak a utility knife in gasoline
on a wood floor, it won't melt. if it does, that makes my hypothesis easy. but it won't.
however, i'm going out on the limb -- if a utility knife is dropped from a hand, straight down, it will easily stick into the floor -- just
above the accelerant, close enough to melt without splashing.
again, barring finances and facilities, I can't check this. but I believe the gasoline will provide well above the 450 melting point.
where does the blade go? it's red hot in a piece of wood. it falls over. the zinc is heavy so it stays in place, the blade goes flying from the water.
it is either not seen or ignored in the rubble, because it certainly does not look like a murder weapon.
question -- Is the neck wound consistent with a utility blade cut?
Are there photos with a blade anywhere?