Ah poor old brendan dassey, not a shed of evidence against him and locked up for what 14 years now? Some waste of a life.
Why would he want this to go unnoticed ?
Well, his narrative is and was always that Avery had 4 days after the crime to clean up, that he forensically cleaned the place with a "Rug Doctor", and so not a single drop of blood or DNA was found in there.
He recently posted on Twitter that no DNA of Jodi's, Teresa's, or Brendan's was found in that room, and that showed how well Steven had cleaned up. It peeked my curiosity that he would mention Jodi, since her DNA sample was never collected to compare evidence to. (Another lie !)
While checking lab reports used at trial I also realized that Sheryl Culhane (hair lady) had not in fact checked swabs from that room for DNA, because none of these had any trace of blood.
As per trial transcripts, there were too many hairs collected in the vacuum and that room to check, so hair wasn't tested. In fact, there were 8 hairs lifted specifically from the bedside locker and headboard that could possibly have been tested, it could have yielded precious info since in confession BD said they cut Teresa's hair and placed it on the locker. These 8 hairs are tagged and bagged and locked away in evidence, and not sent to lab that I can see.
So yeah. No evidence to corroborate Brendan's confession, a suspicious crime scene processing protocol, and a narrative that the supposedly sterile room was due to Steven's diligent cleaning skills (you should check out newly released photographs of the place to assess how NOT cleaned it looked).