1 - 2
http://www.nydailynews.com/new-york/dna-found-sarah-fox-evidence-ows-chain-belong-sloppy-city-worker-sources-article-1.1112436
I learned about this story on the Huffington Post (where it's still on the main page), and it was first reported by NBC. I'm not sure this one counts as a liberal cover-up.
1 - 2