The latest Secret Service scandal has raised an unusual question: How does an agent manage to leave a stray bullet behind?

The issue comes up in the case of two senior supervisors removed from President Obama’s protective detail, which began when one of the men allegedly left a Secret Service bullet in the room of a woman he met at the Hay-Adams Hotel bar last May.

According to two former Secret Service agents, the answer is straightforward: Senior supervisor Ignacio Zamora Jr. was likely attempting to clear a round from the chamber of his Service-issued Sig Sauer P229 semiautomatic pistol in order to secure it after joining the woman in her room.

The agency’s standard operating procedure requires that all armed agents carry their weapon with a fully loaded magazine of 12 bullets, along with a thirteenth round already loaded in the chamber and ready to fire, the former agents said. There is no safety device on the weapons because they must be ready in case of emergencies, they said.

“In order to fire the gun, all you need to do is pull the trigger,” said one former agent, who has worked with Zamora.

“He might have been trying to make the gun safe,” this agent said. “To remove the ammo, the first thing you do is remove the source, the magazine. Because if you try to slide the rack first, whatever is in the chamber will pop out but another bullet will be inserted. To prevent that you remove the magazine, so there’s no more source. Once you remove the magazine, you slide the rack to get whatever bullet is in the chamber.”

One person who was briefed on the details of the case confirmed that Zamora had been attempting to secure the weapon after the woman expressed discomfort with it. She later asked him to leave, which he did before realizing he had left the bullet behind, the person said. His attempt to retrieve it alarmed hotel management, which contacted the Secret Service.

A broader review of Zamora’s conduct found that he and another male supervisor had been sending improper emails to a female subordinate, leading to their removal from the protective detail.

The case came as the agency is attempting to recover from a 2012 scandal in which more than a dozen agents were caught cavorting with prostitutes in Cartagena, Colombia. Whistleblowers have told a Senate committee that Secret Service agents and managers have engaged in sexual misconduct and other improprieties across a span of 17 countries in recent years.

White House press secretary Jay Carney said Friday that Obama has “absolute confidence in the leadership at the Secret Service” despite the agency’s woes.

The former agent who worked with Zamora said the agency generally frowns on agents removing the bullet from the chamber because fiddling with the chamber could result in an accident. He said agents are given trigger locks to secure their weapons at home.

But another former agent, who also has worked with Zamora, said he and his fellow agents did not travel with their locks, which are bulky like a padlock and hang off the back of the trigger.

In cases when they do not have the lock, agents are allowed to clear the chamber to secure their firearms.

“I’ve been in situations at other people’s houses where I wanted to take off my coat and I don’t want to walk around the house looking like a Texas Ranger,” the second former agent said. “I take the gun out of the holster, clear the weapon and put it in my car, in the trunk.”

Both former agents noted that another reason to clear the chamber is to be sure that other people do not pick up the weapon and shoot it.

The two former agents said that losing a single bullet would not have resulted in major recriminations inside the Secret Service. They said managers did not account for each bullet issued to agents, who often have three or four boxes of ammunition.

However, if the bullet were found in the room and identified as coming from Zamora’s stash, it could raise difficult questions, the agents said.

The first former agent recalled of his days on the road: “What I would do is just get the gun and stick it in a drawer. I never fooled around with it.”