About the crime scene:
That Joy Risker was stabbed and later dismembered would lead one to think that there had to be copious amounts of blood between the bedroom and the bathroom--the two places where blood evidence was found. That Sheila admitted that she cleaned up blood in the house at Sean's request might leave the impression that she had mopped up vast amounts of blood, and had to have known that Joy was dead, or at least badly injured. But is that the correct impression?
Just how much blood was there in the house? There is no way to tell for sure.
This is what we know from testimony and the evidence police gathered.
When police criminalists arrived to the scene, a month after the crime to which Sean Goff had just admitted, found small amounts of bloodstains. The photos taken by police show very tiny spots--barely visible to the naked eye. It was surprising that there were in the bathroom, where for a month after Joy's "disappearance," the rest of the family had regularly carried out their ablutions, miniscule remnants of blood present.
In the bathroom and Joy's bedroom, police sprayed luminol, a substance that causes blood to fluoresce. Luminol also fluoresces in the presence of chlorine. Blood is a difficult substance to clean and luminol can detect traces of blood even after it has been cleaned up. In the house, the luminol turned up next to nothing. If Joy's blood had spilled in the bathroom, on the floor and the walls, police would have expected the grout between the tiles to absorb the blood. And if bleach had been used, that should have fluoresced too. There was not the kind of glow they expected. What did it mean? Why didn't the luminol light up in the bathroom?
Sheila testified that she did not clean up lot of blood to clean. She said she saw very tiny droplets on the wall in Joy's room, and a few places in the bathroom and in the shower. She said she cleaned the shower curtain of some droplets, but ended up tossing it out in the trash.
Sean would later testify that he had cleaned the house before he left with Joy's body. And he also said he'd returned home that Sunday, before Sheila, but said he didn't do any more cleaning.
What could account for the "lack" of blood at the scene? At least two possibilities, not mutually exclusive of each other, exist. A thorough clean-up, as admitted to by Sean Goff, and, according to the prosecutor’s scenario, the two rolls of plastic sheeting Sean had purchased on September 13th had been put to use six nights later during Joy's murder.
--Charmaine Lewis, Dateline producer