SAN FRANCISCO — When the police apprehended a suspect for the shootings at The Capital Gazette’s newsroom in Annapolis, Md., on Thursday, he refused to divulge his name. So the authorities identified the man, Jarrod Ramos, using a different method: facial recognition technology.

The revelation shone a spotlight on just how easily and how quickly officials can pinpoint suspects using a technology that is increasingly pervasive in law enforcement. Over the past few years, facial recognition has been quietly adopted by the authorities across the United States — including at the local policing level — and become part of the standard law enforcement toolkit.

Sixteen states let the Federal Bureau of Investigation use the technology to compare the faces of suspected criminals to driver’s license and ID photos, according to a report from the Georgetown Law Center on Privacy and Technology. And thanks to recent improvements to facial recognition by some of the world’s largest tech companies, its influence in policing is likely to grow.

“Face recognition is one of the most important developments in crime fighting since the discovery of fingerprinting in the 19th century,” said Joseph J. Atick, a pioneer in face recognition technology and executive chairman of ID4Africa, which works with African governments to institute national identification systems. “It’s hard to imagine a police department in the United States with more than 10 to 15 cops in it that does not have access to face recognition.”