From the comments:

And this is why people (me at least) don’t want all encompassing data collection.

If the police have the data, absent some law protecting it (sometimes even if it does!) they WILL use it.

Hell, someone was probably just trying to make their job easier. “Well we got some DNA evidence from the crime scene. What DNA databases do we have other than criminals? Let’s run it through those, maybe we will get a hit.”

Doesn’t make it ethical or okay.

azazel1024