The Los Angeles Times reported it has obtained a copy of a memo from David Aguilar, deputy commissioner of the border protection agency, to Homeland Security Secretary Janet Napolitano. The memo says the inspector general in the Department of Homeland Security is doing its own review in addition to one by an independent outside group.
Under current rules, border agents can use deadly force on people suspected of throwing rocks, such as occurred when a 16-year-old was shot dead in October in Nogales, Mexico.
At least 16 people have been killed since 2010 in confrontations along the border involving U.S. agents.
Shawn Moran, vice president of the National Border Patrol Council, which represents agents, suggested the Mexican government should take some responsibility.
"They refuse to police their northern border and they allow free rein by criminal organizations," he said "But when one of their citizens is killed after assaulting a Border Patrol agent, they raise hell."