My thought was that when the jogging incident happened and they submitted DNA from the jogger, say under her fingernails, that it sat in the database with "no match". So they had a sketch, but no name of someone to go after. Then they submitted DNA from things found within his home, which could be his, his wife's, and say, Dani's. Now this DNA makes a connection to the former "unknown Floyd DNA" that was sitting in there without a match. But now it has a name tied to it if they took something from his home that the "knew was only Floyd DNA" to create a profile for him.
Again, totally a guess...and I don't even know if that makes sense like it does to me. But I read earlier that people can have DNA already in the system, but no connection to a case, and then when it's reprocessed or whatever they do, it can form a hit/match years later from samples already in there. I could be totally wrong though.
http://www.forensicsciencesimplified.org/dna/how.html
Found this....
http://dnapolicyinitiative.org/resources/frequently-asked-questions/
Scroll down to "What is a DNA Database?
When a new crime scene DNA profile is added to the database it is searched against all the other DNA profiles stored on the database. The crime scene profile might match with stored DNA profiles from other crime scenes, indicating a link between these crimes. Or it might match with an individual’s DNA profile, suggesting that they could be a suspect for the crime. When a new DNA profile from an individual is added to the database it is searched against all the stored crime scene DNA profiles on the database. Again, a match may indicate that the individual may be a suspect for the crime. This process is known as ‘speculative searching’ and it results in reports of matches that can be sent back to the police for further investigation. The police will retrieve the name and other identifying information of the individual from the DNA database so they can interview, arrest and perhaps prosecute them for the crime. A DNA database of individuals’ DNA profiles is not needed in order to compare the DNA profiles of known suspects with DNA left at a crime scene. Its only purpose is to introduce new suspects into the investigation via unexpected matches known as ‘cold hits’.
