Just because the police can do something, doesn't mean they should be legally allowed to do it. Before all the fingerprint comments start, I will remind folks that DNA is categorically different than fingerprints. Yes, both can identify an individual. But that is like saying both a driver's license and a smart phone can be used to identify a person. If you search someone's smart phone, you have boatloads more information. DNA is becomming more useful by leaps and bounds every year. This is too much information for the government to just blythely collect and shove into databases with little safeguard against hacking, misuse, and abuse. There seriously needs to be a national discussion and laws passed. It is sad that this is unlikely to happen.
Some (ie, those part of the security industrial complex) do not want this discussion because they fear a curtailment of police powers. Others do not want it because they don't trust our current government to not bend this discussion into the interests of the wealthy.
Luckily the supreme court is a bastion of ethical behavior and impartiality . I trust this outcome is based on a rational forward-thinking, wise consideration.