However, that law offers an exception for "unusual cases where the interests of justice would best be served." Karlin said she found the Du case unusual for several reasons. She cited Du's lack of a criminal record, found that Du had fired under "great provocation" and said the crime might never have been committed had the gun not been altered to make it fire more easily.
Reiner argued that Karlin was not entitled to find the case unusual and that her ruling was therefore illegal, but the appeals court found Karlin's reasons valid.
That left the court to consider whether Karlin had abused her discretion, as Reiner asserted. The court found that she had not.
Reiner said Tuesday's decision was not surprising, and experts in appellate law agreed.
Attorney Dennis Fischer, who specializes in criminal appeals, said the ruling is "completely within the mainstream" of how appeals courts decide such cases. Of Reiner's attempt to reverse the decision, Fischer said: "They were really swimming upstream on this case."
Fischer also noted that because the ruling will not become final for 30 days, any appeal is likely to be decided after the June 2 election. "When Election Day happens," Fischer said, "this decision will be the only decision on the books."
Karlin's backers in the legal community, many of whom claimed the outcry over her decision would intimidate other judges into buckling under public pressure, were elated.
"This is a victory for judicial independence," said attorney Charles T. Mathews, who has organized a group of lawyers to support Karlin. "It tells every judge in the state of California that they are going to be allowed to use discretion."
But Karlin's foes were sorely disappointed. They have until July to gather the necessary 301,000 signatures to put their recall petition on the ballot; Compton Councilwoman Patricia Moore said 280,000 people have already signed.
"This (ruling) is the incentive that will cause citizens to finish it up and to send a message loud and clear to the justice system," Moore said. "I've gotten over 50 calls just in the couple of hours since we heard about it. Since the system won't do what's right for us, we're going to take charge and show the system who it's supposed to be working for."
Times staff writer Stephanie Chavez contributed to this story.