A federal appeals court has declared a 3-year-old law that requires federal inmates and parolees to give blood samples for the FBI's DNA database (searchto be an unconstitutional invasion of privacy.

In a 2-1 decision handed down Thursday, the 9th U.S. Circuit Court of Appeals  overturned the DNA Analysis Backlog Elimination Act of 2000 (searchon grounds that the routine sampling denied inmates and parolees of their Fourth Amendment protection against illegal searches.

Law enforcement officials, according to the opinion, wrongly took the blood samples because there was no legal suspicion that the convicts were involved in other crimes.

The Justice Department declined comment.

Government lawyers had argued that taking blood was no different than taking fingerprints. Two of the panel's three judges, however, rejected that proposition as a "false analogy."

Equating fingerprints and blood "obscures the constitutional difference between invasive procedures ... and an examination or recording of physical attributes that are generally exposed to public view," wrote Judge Stephen Reinhardt (search).

The ruling could have a sweeping impact on criminal cases in California and other states.

Blood samples taken from federal prisoners and those on supervised release have been used to convict hundreds of people on crimes such as murder and rape. It was too early to say whether those convictions would survive, said Monica Knox, a deputy public defender of Los Angeles.

Knox also said the decision, if it stands, could nullify state laws that require the taking of blood from inmates and parolees. The court covers Alaska, Arizona, California, Hawaii, Idaho, Montana, Nevada, Oregon and Washington state.

"Most states have similar laws," Knox said. "This could gut those."

Most of the 1.4 million genetic profiles in the FBI's database are from prisoners and parolees, said bureau spokesman Paul Bresson. The FBI does not track the number of samples in the database that match physical evidence collected from unsolved crimes.

California, however, does track that number, said state Attorney General Bill Lockyer. Matches have occurred about 400 times, including one that led to the conviction of a man in the 1993 rape and murder of two San Diego youths.

Scott Erskine, 40, was serving a 70-year term on unrelated rape charges when his blood matched semen taken from the 1993 crime scene. Last year, his blood also was linked to evidence taken from the 1989 rape and slaying of a Palm Beach County, Fla., woman.

It was not immediately clear whether the decision would allow those who have given blood to have it withdrawn from the databank, for use by police nationwide.

The case decided Thursday concerned Thomas Kincade, on parole for a Los Angeles bank robbery who refused to give a sample. A lower court judge had upheld the law.

Knox said she expected legal battles on whether the ruling, if it survives appeals, would be applied differently to parolees and those still in prison.

"I believe the opinion applies to prisoners, too," Knox said. "There will be more litigation on this, I'm sure."

The San Francisco-based panel said its decision does not overturn rules that, for example, allow random drug testing of students who play school sports.

In dissent, Judge Diarmuid O'Scannlain said recent Supreme Court precedents did not require the court to conclude the DNA act was unconstitutional because convicts have fewer rights than nonconvicts.

In addition, he said the court in 1995 sided with an Oregon law requiring certain convicts to submit to a DNA registry -- a ruling he said should stand.

The 9th Circuit is the most liberal and overturned federal appeals court in the country. The court's three-judge panels are known for several contentious rulings, including one that declared the Pledge of Allegiance unconstitutional in public schools and a decision last month that postponed California's recall election. That ruling was later overturned by a larger 9th Circuit panel.