I was thinking, I would imagine this woman is also very sick over the fact her hair was found on these bodies.
I know she did not do this it was on him when he went there but it would certainly bother me if MY hair was on a poor murdered girl and there is at least one of her hairs on each of the three of them.
My guess ... three-ways, then (maybe) hubby alone with the hooker, for no obvious reason he then offs them. Or they both participate in it. Sick.