Final answer:
The Meredith Kercher case featured two opposing views on DNA evidence found on a bra-clasp: one suggesting direct involvement of the accused, and another, secondary transfer, raising doubts about the DNA's reliability as conclusive evidence of guilt.
Step-by-step explanation:
The case of Meredith Kercher involved complex DNA evidence which led to two alternative propositions concerning the DNA found on her bra-clasp. The first proposition suggested that the DNA belonged to one of the accused, implying direct involvement in the crime. The second proposition contested this, positing that the DNA could have been transferred there via secondary transfer, which means it could have been innocently transferred onto the bra-clasp through casual contact at some point before the murder, casting doubt on the reliability of the DNA as evidence of guilt.