An illustration of the DNA double helix
California's database of DNA samples has grown to nearly 2 million since Proposition 69 went into effect in 2009. That law expanded DNA collection, including directing law enforcement to take cheek swabs from individuals arrested on suspicion of crimes like murder, attempted murder, and rape.
The idea was to make California's database comprehensive and up the likelihood of solving cases involving DNA evidence, cold cases in particular. Since its implementation, the California Attorney General's office says the monthly rate of hits signaling a match between evidence and DNA profiles has doubled.
But critics wonder why it's necessary to take DNA samples from people who have merely been arrested for — rather than convicted of — crimes. And the ACLU of Nothern California will argue at the 9th Circuit on Wednesday that arrestees should not have to give DNA samples to law enforcement.