The U.S. Customs and Border Protection's Offices of Border Patrol and Training and Development say it is inspecting the quality of agents' M4 carbines throughout Border Patrol sectors nationwide, and that's why agents have been required to turn in the weapons. But agents have told News 4 Tucson , some of these M4s have not been replaced. And agents are required to share rifles.

"There's a lot of agents that are pretty upset over it," said Art del Cueto, president of the Border Patrol's Tucson Sector union. "We know it's a dangerous job. We know what we signed on for but we want to have as much of the equipment as we need to perform the job."

Customs and Border Protection released a statement to the News 4 Tucson Investigators last week, stating: "CBP's Offices of Border Patrol and Training and Development are jointly inspecting the serviceability of M4 carbines throughout Border Patrol Sectors nationwide. Some of (the) inspected M4 carbines were deemed unserviceable and removed from inventory to alleviate safety concerns. Inspections will continue to ensure the unserviceable M4 carbines are repaired or replaced for reintroduction into the field. No further information is available at this time."

Jeff Prather is a former drug enforcement agent who now runs the Warrior School in Tucson. He says agents have reached out to him about the rifle shortage. He believes removing some of the rifles may be politically motivated. He says he was told that many of these guns are being removed for issues that are easily repaired like the firing pin and bolt.