I am with you on all that being a possibility...but I was worried about the existing DNA from the crime. There have been multiple sources in the days since Karr's arrest hit the airwaves about the DNA possibly NOT being enough and/or having been somehow compromised. That's my only worry.
the "compromised" comments I heard - only referred to the fingernail DNA. the sample on the underwear is not compromised, but was reported as being incomplete, but that may be changing now too.
A lot of the people commenting on the DNA in the media recently aren't aware of that latest development, so it has been confusing.