I've been most suspicious of the bra clasp DNA. I think that Steffi did "find" MK's DNA on the blade but clearly violated multiple rules and protocols. I think she hid records to cover her lack of proper procedure. I doubt very much that she thought the kids were innocent. Clearly they could have put an abundant amount of MK's DNA on the blade if they were framing the kids.
The police detective (Volturno) recorded Quintavalle and Curatolo's statements that countered what they eventually said.
What we don't know is how much exculpatory evidence they destroyed if they did.
It wouldn't shock me one bit to discover that the semen stain was tested and held back. The same goes for the mysterious hair that disappeared.
