SAN FRANCISCO (AP) — A federal appeals court appeared ready last year to strike down as an unconstitutional invasion of privacy a controversial California law requiring police to collect DNA samples from every person arrested in the state.

Then the U.S. Supreme Court ruled 5-4 to uphold Maryland’s similar — but narrower — law. The 9th U.S. Circuit Court of Appeals then ordered lawyers on both sides to refashion their legal arguments in light of the high court ruling.

On Monday, a specially convened 11-judge panel of the 9th Circuit will hear oral arguments in San Francisco.

California Attorney General Kamala Harris and the Obama administration are both urging the court to uphold California’s law as a constitutional and powerful law enforcement tool.

Law enforcement officials say expanding DNA collection helps in solving so-called cold cases through matches in California’s DNA database, which has nearly 2 million samples. The samples are compared to DNA evidence kept from long-ago crimes in hopes of finding a match. More than 10,000 suspects have been identified through the database in the last five years.

Voters passed the law in 2004 to go in effect in 2009. In 2009, the American Civil Liberties Union filed a lawsuit on behalf of a woman who was arrested at an Iraq War protest but never charged.

The ACLU argues that the law is unconstitutional because not all arrestees are charged with a crime. It argues that California’s law is different from the Maryland law upheld by the Supreme Court because Maryland collects DNA only from those arrested for serious offenses.

“Unlike Maryland, California’s DNA law includes not only individuals arrested for violent felonies but also people arrested for nonviolent offenses such as joyriding, simple drug possession, and shoplifting beer,” ACLU Michael Risher wrote in a legal filing.

Risher also noted that Maryland officials automatically destroy DNA samples collected from arrestees who are not charged. Persons arrested in California but not charged must apply to the state for destruction of their DNA samples.

“These differences, however, are not constitutionally significant, and do not distinguish” between the Maryland and California laws, state deputy Attorney General Daniel Powell argued in court papers.

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