To my knowledge they have not said it specifically but they have said there is "plenty" of evidence, so draw your own conclusion. Plus, inherently in a situation like this, there is DNA.
Yeah, probably lots and lots of DNA of every possible type from lots and lots of people.
Good luck sorting that out.
It's very common in stabbing cases for the killer to cut themself in the process of stabbing someone.
The blood science and DNA evidence related to blood splatter isn't all that hard to figure out.
Matching the blood evidence and DNA to a viable suspect can be frustrating, if after the initial tests to rule out suspects yields no fruit.
