By Elliot Spagat, Associated Press

SAN DIEGO — U.S. Customs and Border Protection found that employees acted properly when they fired guns in four incidents dating back to 2012 — including two that left two people dead.

The findings were released Thursday by the agency’s National Use of Force Review Board, which was established in December 2014 amid widespread criticism that the nation’s largest law enforcement agency was slow to investigate such incidents and lacked transparency.

The cases involve a Border Patrol agent who fired from Texas at rock-throwers in Mexico, a heavily armed murder suspect who was fatally shot as he fled a Texas house when a Border Patrol agent and other law enforcement officers opened fire, a Border Patrol agent who fired at rock-throwers in Arizona and an Office of Air and Marine crew that fired warning shots and crashed into a vessel off the Southern California coast carrying immigrants, one of whom died.

The reviews are the board’s first under its mandate to review uses of lethal force and other serious incidents once federal, state and local prosecutors decline to pursue criminal charges. It has opened investigations into 14 other cases.

Customs and Border Protection says officials have fired their guns in 223 incidents from the 2011 to 2015 fiscal years, including 28 last year. Rock attacks on agents have been among the most controversial, with critics saying agents have overreacted and defenders saying stones can be deadly weapons.

Here are descriptions of the four incidents provided by Customs and Border Protection:

—On Oct. 2, 2014, a Border Patrol agent fired one shot at a rock-thrower in Mexico who posed “an immediate threat.” Agents who were patrolling the Rio Grande near Escobares, Texas, saw three abandoned rafts and eight people fleeing. They found 682 pounds of marijuana nearby.

The suspects threw baseball-sized rocks from Mexico at a Border Patrol vessel that got stuck on a sandbar, leading agents to fire 18 pepper-spray projectiles. The assailants dispersed after the agent fired his rifle; no injuries were reported.

—On July 22, 2014, a Border Patrol agent shot at a murder suspect in La Joya, Texas, who barricaded himself in a home and fired about 15 shots at law enforcement officials. Agents responded to a call for assistance from Edinburg, Texas, police. Ten law enforcement officials, including a Border Patrol agent, fired their guns at the man, who was struck several times and died at the scene.

—On May 5, 2012, a Border Patrol agent who was chasing people who had crossed the border illegally from Mexico fired one shot at a rock-thrower in a mountainous area near Nogales, Arizona. The agent said the assailant threw a rock that was larger than a softball from about 25 feet away. There were no reports of injuries.

— On June 17, 2015, a crew of Customs and Border Protection Office of Air and Marine fired two warning shots and another shot to disable the engine of a boat carrying 20 people illegally from Rosarito Beach, Mexico, to Southern California. The smuggling vessel, which had been steered erratically while trying to evade authorities, made an abrupt turn about 10 miles from Solana Beach, California, and slammed into the government vessel, throwing the immigrants overboard. One female passenger died.

The Southern Border Communities Coalition, which has pressured the agency to overhaul practices, welcomed the effort to improve public disclosure but expressed disappointment with the findings and said the agency still had long way to go on how it reports on use-of-force incidents and holds agents accountable. Its director, Christian Ramirez, said the conclusions were “too little and too late for dozens of families who continue to wait for CBP leadership to take bold and decisive action to end the culture of violence and impunity that has plagued CBP for years.”

The National Border Patrol Council, which represents agents, said it hoped the findings would silence some critics.

“We’re happy to see some transparency from Customs and Border Protection,” said Shawn Moran, a union spokesman. “We hope that that transparency will show just how difficult it is for Border Patrol agents to go out there every day.”

To Learn More:

67 Border Patrol Shooting Internal Investigations; No Criminal Charges (by Noel Brinkerhoff, AllGov)

U.S. Courts Struggle with Case of Border Patrol Agent who Shot to Death a Teenager on the other Side of the Border (by Noel Brinkerhoff and Danny Biederman, AllGov)

Border Patrol Sued for Killing a Picnicker in Mexico (by Noel Brinkerhoff, AllGov)