STEVE INSKEEP, HOST:
In San Francisco on Tuesday, a deputy public defender made news when she challenged police who were trying to take pictures of her client. The police arrested her. Now, on a video of this incident, a police sergeant warns her, quote, "I will arrest you for resisting arrest." So how is a charge like that possible? Our law enforcement correspondent Martin Kaste explains.
MARTIN KASTE, BYLINE: Arrested for resisting arrest - it's kind of like being kicked out for refusing to leave. But this logical head-scratcher has a long track record. Criminology professor David Carter says it's usually an aggravating offense when you're already being arrested for something else.
DAVID CARTER: If you do not comply with that and you fight me off, it's a resist. You got to have the arrest to have a resisting arrest.
KASTE: But as a standalone charge? He says that's rare. San Francisco police spokesman Albie Esparza says it was justified in this case because the public defender was interfering with police work.
ALBIE ESPARZA: We stand behind the sergeant's actions, and it appears that there is no violation of any department policy or any law.
KASTE: The public defender hasn't been charged yet, but she's being investigated for violating a California law that includes resisting arrest and obstructing police. Some see this incident as part of a larger pattern of police using charges like these as an excuse to arrest people unjustly. In Seattle this week, police apologized for the way this officer treated an African-American man who was walking down the street with a golf club.
(SOUNDBITE OF ARCHIVED RECORDING)
CYNTHIA WHITLATCH: If you do not put the golf club down, you will be subject to arrest for obstruction.
KASTE: The man dug in. Why should he drop his golf club? But by arguing, he may have made the cop feel compelled to arrest him. New York criminal defense attorney Nathaniel Burney calls this the boss dog mentality.
NATHANIEL BURNEY: I'm in charge, and you shall not resist me. You shall not contradict me. You're going to do what I say at all costs.
KASTE: And when you don't show the expected degree of compliance, that's how you can end up being arrested for resisting arrest. Martin Kaste, NPR News.