Is there any evidence of such a clean up?
It is of a little weight that Meredith's blood is mixed only with Amanda's especially in Filomena's room and in the hallway.
What makes you think that luminol hit in Filomena's room (or the hallway for that matter) was blood? Doesn't the fact they all tested negative for blood with TMB hold any weight? Does the fact Stefanoni omitted that from her comprehensive technical report,
the RTIGF, and then
lied about it in court hold any weight?
In other words why would anyone still allow the prosecution the
assumption that they were blood when they tried to hide the test that falsified it and lied about doing it in court?
Stefanoni's own testimony (p.177--27 of the PDF) on TMB tests (in general) was this:
GIUDICE Però laddove è negativo mi pare di capire che lascia abbastanza convinti del fatto che non lo sia?
RIPOSTA Si, che non e sangue, che non lo sia, si.
JUDGE: However where the result is negative I’m given to understand that it’s almost certain that it is not [blood]?
ANSWER: Yes, it’s not blood, it is not, yes.
The possibility the hits were diluted below the threshold of TMB but within the luminol detection range was a low probability scenario invented because they'd been caught hiding the negative TMBs and lying about them in court. If you think on it
every test result can be 'hypothesized' away like this, it is most certainly not strong evidence of those hits being blood, the strong evidence on this issue is with the negative TMBs--which is why they hid them and lied about it.
As for the 'only' DNA profiles being Amana and Meredith's, what are you basing that remark on? Wouldn't you need to have seen the totality of the data collected to make that argument? This is part of why the EDF's are so crucial in cases like these where the prosecution can cherry-pick what data they want to show and withhold what they do not want anyone to see without consequence.
The sink DNA is of no weight at all, particularly the way it was collected.
Here's another guy with FBI experience,
Jim Clemente, making that same point. His arguments regarding prosecution misconduct and the condition of the crime scene are very relevant to the luminol hits as well.
Did they do luminol in Meredith's room?
If they did it's not in the crime scene videos and I've not seen or heard anything about it. The reason for that may be there's no reason to suspect there was a clean-up at the scene, and a number of reasons to think there wasn't, so it may not have been done (initially) by the
Polizia Scentifica for that reason.