WASHINGTON — Border Patrol agents have deliberately stepped in the path of cars to justify shooting at the drivers and have fired in frustration at people throwing rocks from the Mexican side of the border, according to an independent review of 67 cases that resulted in 19 deaths.The report by law enforcement experts criticized the Border Patrol for “lack of diligence” in investigating U.S. agents who had fired their weapons. It also said it’s unclear whether the agency “consistently and thoroughly reviews” use-of-deadly-force incidents.U.S. Customs and Border Protection, which had commissioned the review, has tried to prevent the scathing 21-page report from coming to light.House and Senate oversight committees requested copies last fall but received only a summary that omitted the most controversial findings — that some border agents stood in front of moving vehicles as a pretext to open fire and that agents could have moved away from rock throwers instead of shooting at them.The Los Angeles Times/Tribune Washington Bureau obtained the full report and the agency’s internal response, which is 23 pages. The response rejects the two major recommendations: barring border agents from shooting at a vehicle unless its occupants are trying to kill them, and barring agents from shooting people who throw things that can’t cause serious injury.The response, marked “Law Enforcement Sensitive,” says a ban on shooting at rock throwers “could create a more dangerous environment” because many agents operate “in rural or desolate areas, often alone, where concealment, cover and egress is not an option.”If drug smugglers knew border agents were not allowed to shoot at their vehicles, it argues, more drivers would try to run over agents.New Homeland Security Secretary Jeh Johnson is “reconsidering the response” to the two recommendations, a Homeland Security official said Wednesday. The official spoke on the condition of anonymity to discuss internal deliberations.Mexican authorities have complained for years that U.S. border agents who kill Mexicans are rarely disciplined and that the results of investigations are not made public for years. Critics warn that more deaths or abuses are inevitable unless stricter limits are imposed on the use of lethal force.“There needs to be a level of accountability if you want to change the culture and the pattern,” said Christopher Wilson, an expert on U.S.-Mexico relations at the Woodrow Wilson Center, a think tank in Washington. “People are being killed that don’t need to be killed.”The review was completed in February 2013 by the Police Executive Research Forum, a nonprofit research and policy organization in Washington that works closely with law enforcement agencies. Experts from the group were allowed to examine internal Border Patrol case files on 67 shootings from January 2010 to October 2012.‘Get out of the way’The authors said evidence in the files suggests that some border agents stood in the road to shoot at drivers who were trying to avoid arrest and who posed no lethal threat to them or others.“It is suspected that in many vehicle shooting cases, the subject driver was attempting to flee from the agents who intentionally put themselves into the exit path of the vehicle, thereby exposing themselves to additional risk and creating justification for the use of deadly force,” the report reads. In some cases, “passengers were struck by agents’ gunfire.” “It should be recognized that a half-ounce [200-grain] bullet is unlikely to stop a 4,000-pound moving vehicle, and if the driver … is disabled by a bullet, the vehicle will become a totally unguided threat,” it says. “Obviously, shooting at a moving vehicle can pose a risk to bystanders including other agents.”The authors recommended training agents “to get out of the way … as opposed to intentionally assuming a position in the path of such vehicles.”They also recommended that the Border Patrol adopt police policies used in most U.S. jurisdictions, which bar officers from firing at a moving vehicle unless deadly force is being used “by means other than a moving vehicle.”Border Patrol officials defended the use-of-force policies, arguing that agents need broad flexibility to protect themselves and the nation’s borders.