Marshall Zelinger reports (emphasis added by me):
It may not be until the middle of October when we find out if the state’s new DNA law can help solve any cold cases.
At 12:01 a.m. Thursday, law enforcement could begin getting a DNA sample from anyone arrested and suspected of a felony. Prior to Thursday, only fingerprints were taken when the person was arrested and processed.
Before the law, DNA samples were only taken once a person was convicted of a felony.
[…]
If a person arrested for a felony is not charged with a felony, that DNA sample is supposed to be destroyed, but the person has to petition a court for that to happen.
Colorado was the 16th state to pass a law like this in 2009. There are now 24 states with similar DNA laws.
They are counting on people not petitioning the court so that they can keep more DNA, I would guess.
The ACLU of Colorado had indicated that they would be mounting a legal challenge to the law, but I do not see anything on their site that refers to any filing.