Just having a look at the list of DNA test results on the FOA site. Is it true that Amanda and Meredith's DNA was found in a shoe print revealed by luminol?
That seems quite significant, if so. Since all the other shoe prints were Rudy's, it seems logical to assume this was his too, perhaps missed by the police or too faint to be seen with the naked eye. Shoes don't have DNA, obviously, so the only ways for Amanda's DNA to have gotten there are either that it was latent and there already, or that Rudy had trodden in something containing her DNA and was tracking it through the house. It also seems very likely that the faint trace of Amanda's DNA in Filomena's room came from the same source. the shoe-wearer stepping into the room and transferring a much smaller amount of her DNA to the luminol-revealed stain found there.
From Friends of Amanda:
Investigators took swabs of each of the six bare footprints they detected with luminol. These swabs were not tested to confirm the presence of blood, but they were subjected to DNA testing, with the following results:
LOCATION_____________
DNA PROFILE
Amanda's room..................Amanda
Amanda's room..................Amanda
Amanda's room..................Amanda
corridor............................none
corridor............................none
corridor............................none
These results seriously undermine the prosecution's claim that the bare footprints were made by someone who tracked Meredith's blood into the corridor following the murder. In fact:
* Meredith's DNA was not detected in a single one of the bare footprints
* No test was ever performed to establish that any of these prints were made with blood rather than one of the many other substances that react with luminol.
* No comparable footprints were found inside the room where Meredith was killed.
What about the other stains revealed with luminol?
Along with the bare footprints, three other luminol reactions were observed at the cottage. Two were stains with no shape description, and one was described as a shoe print. The shapeless stains were in Amanda's room and Filomena's room. All were swabbed and subjected to DNA tests. The stain in Amanda's room showed the DNA of both Meredith and Amanda. The stain in Filomena's room showed the DNA of Meredith with a very faint profile corresponding to Amanda. The shoe print was in the corridor, and it showed the DNA of Meredith and Amanda.
These results are unsurprising for samples taken from the floor of a shared residence where all kinds of residue got tracked around. As with the bare footprints, no other test was performed to determine the presence of blood in any of these stains.