WASHINGTON — The number of law enforcement officers who died performing their duties in the U.S. declined by about 20 percent in 2012 after rising the two previous years, a non-profit organization reported Thursday.

The National Law Enforcement Officers Memorial Fund said in a report that 127 federal, state and local officers have died so far on the job. The majority of officers who died were either shot or were victims of traffic accidents, figures show. City and county police officers comprised most of the victims, but the list also includes a prison guard in Indiana who suffered a heart attack while responding to an unruly inmate, a deputy sheriff in Missouri who was fatally shot while responding to an ambush and a Coast Guard officer who was killed off the California coast while pursuing a vessel suspected of smuggling.

The toll is on pace to be the lowest since 2009, when 122 officers died, and this year would be only the second year since 1960 that the number of fatalities has dipped below 130. The organization, which also maintains a memorial wall in Washington bearing the names of fallen officers, reported 165 deaths last year and 154 in 2010.

The decline is heartening after two straight “alarming” years and may suggest that police departments, though still battered by budget cuts, are placing a greater emphasis on officer safety, said Craig Floyd, the chairman and chief executive of the Washington, D.C.-based memorial organization.

“I think officers are approaching these potentially life-threatening situations in a more cautious, focused manner,” said Floyd, noting the increased prevalence of body armor among officers.

Texas had the highest number of law enforcement fatalities at 10, followed by Georgia (eight) and Colorado and Maryland (six each). Thirteen of the officers who died were women.

There have been 49 firearms-related deaths this year, as of Thursday. Those include David Gogian and Jeff Atherly, two Topeka, Kan., police officers shot outside a grocery story last week while responding to a report of a suspicious vehicle, and two West Virginia state troopers, Eric Workman and Marshall Bailey, who were shot during an August traffic stop.  Tom Decker, a police officer in Cold Spring, Minn., and a father of four, was fatally shot last month in what authorities called an ambush killing.

Car crashes, though down from last year, were the leading cause of death — causing 50. A Prince George’s County, Md., police officer who was pursuing a suspected thief died in August when his cruiser ran off the highway and crashed into a ditch. Another officer from the same department died in a crash two months later. Neither officer was wearing a seat belt, prompting Police Chief Mark Magaw to stress the need for officers to buckle up inside their patrol cars.

In Willoughby, Ohio, after Patrolman Jason Gresko’s police cruiser collided with a pickup truck en route to an emergency call in September, Chief Jack Beckwith cited the death as a reminder to his officers to be vigilant in responding carefully to emergencies and told his roughly 50-officer department that “this could have happened to every one of them.”

“It definitely takes a heavy toll on everybody personally that’s on the job,” Beckwith said. “We’re small enough that everybody knows each other very well.”

Other causes of death included job-related illnesses, stabbings and helicopter crashes. Two Atlanta police officers died in a helicopter crash in November during a nighttime search for a missing boy.