Okay. So a person is missing and a jacket they were wearing turns up somewhere, with blood on it. A close relative positively identifies the jacket. The police want to take a blood test/oral swab sample to make sure the blood on the jacket is definitely from the missing person. I'm pretty sure that the person's relative would first have to consent to giving a DNA sample, right? Afterwards, the sample is destroyed and the information purged from the police database - but does this mean that the police couldn't but the DNA sample through their criminal records to check for matches without breaking the law?
Thanks for you help, guys.
ETA: This takes place in Iowa, USA in late 2007 to early 2008.