I'm not posting the bleach thing for the third time. Go find it. If you think all of these stories that have elements that match were made up independently, then you're not trying hard enough (or are you trying too hard?). Blood on the bed? From what?
And bleaching a garage floor isn't that difficult. First, you don't need to destroy "microscopic bits of dna" to begin with. You guys seem to think the forensics guys walk in with a batman dna scanner and let it pan around the room collecting dna samples from every square inch of every surface. For all we know, there could be a microscopic piece of her DNA still in the garage. But for that to be tested, someone first needs to collect it. They don't just take one million cotton swabs and rub down the entire area.
So lets say she was killed on the garage floor. Maybe there's blood stains on 6 square feet of floor space. You could clean that with one bottle of bleach. This isn't master criminal level behaviour. Stop watching CSI
http://www.exploreforensics.co.uk/de...bleaching.html