CrimeBeat Q&A is a weekly feature where police reporter Julie Johnson answers readers’ questions about local crimes and the law.

Can an officer search your cellphone call log or text records to discover how you were using your phone?

— Evan Livingstone, Santa Rosa

Absolutely. With a search warrant.

Or when a phone’s owner gives an officer permission.

Otherwise, an officer generally cannot search through a phone’s data, not even during an arrest, because of a 2014 decision by the U.S. Supreme Court.

In a unanimous decision, the nation’s highest court was clear that the vast quantity of personal information now contained in cellphones deserves protection from warrantless search. In the opinion, Justice John G. Roberts Jr. wrote:

“The fact that technology now allows an individual to carry such information in his hand does not make the information any less worthy of the protection for which the Founders fought. Our answer to the question of what police must do before searching a cell phone seized incident to an arrest is accordingly simple — get a warrant.”

Roberts acknowledged that “privacy comes at a cost” and that the decision would no doubt “have an impact on the ability of law enforcement to combat crime.”

There are exceptions, and the Supreme Court listed several, including cases in which police are pursuing a fleeing suspect or trying to help people who are injured or facing imminent injury.

Santa Rosa criminal defense attorney Mike Li said that since that decision, officers are regularly pushing for people to willingly hand over their phones during traffic stops and arrests.

So, should a person agree if an officer asks to look through his or her phone?

Li, who was a prosecutor for five years with the Sonoma County District Attorney’s Office before he entered private practice in 2011, said that even people who have done nothing wrong and feel they have nothing to hid should consider whether anything could be misconstrued as evidence of criminal activity.

“Criminal defense attorneys will tell you: Don’t give up 4th and 5th amendment rights, don’t ever talk to the cops and never consent to a search,” Li said.

Submit your questions about crime, safety and criminal justice to Staff Writer Julie Johnson at julie.johnson@pressdemocrat.com. On Twitter @jjpressdem.