In my opinion, if you are thought to have committed a crime, DNA is just like fingerprints. If you are suspected of a crime and you know you are innocent, it can clear you, but if you aren’t, well suffer the consequences. There has been a lot of debate about this being an invasion of privacy, however, you kinda give that up when you commit crimes against the rest of us. With my love of DNA, I am 100% for it. It should be in codis, which according to wikipedia is:
The Combined DNA Index System (CODIS) is the United States national DNA database created and maintained by the Federal Bureau of Investigation. CODIS consists of three levels of information; Local DNA Index Systems (LDIS) where DNA profiles originate, State DNA Index Systems (SDIS) which allows for laboratories within states to share information, and the National DNA Index System (NDIS) which allows states to compare DNA information with one another.
The CODIS software contains multiple different databases depending on the type of information being searched against. Examples of these databases include, missing persons, convicted offenders, and forensic samples collected from crime scenes. Each state, and the federal system, has different laws for collection, upload, and analysis of information contained within their database. However, for privacy reasons, the CODIS database does not contain any personal identifying information, such as the name associated with the DNA profile. The uploading agency is notified of any hits to their samples and are tasked with the dissemination of personal information pursuant to their laws.
With the advent of Phenotyping, familial DNA, which tells that you did NOT commit the crime but someone you are related to did. Wow! You might have some inkling of just who that relative might be (this type of DNA sample would have to be requested by law enforcement and you would have to willingly consent to it to help them find their man or confirm it on someone who they felt was suspicious but they didn’t have DNA on.
Read the article Supreme Court Rules DNA Can be Taken After Arrest. 2012 was the last information I could find on the states that will allow DNA testing upon arrest and there were 28 states, I am sure that has probably increased by now.