A D.C. police officer accused of threatening Michelle Obama last summer maintains that he made a sarcastic quip while inadvertently displaying an image of a gun on his smartphone, his attorney said at an administrative hearing Wednesday that will determine his future on the force.

But a colleague said she perceived Officer Christopher Picciano’s words at a Washington restaurant as a threat. She said Picciano deliberately showed her the picture and said, “This is the gun I plan to do it with.” The witness said she waited several hours before reporting it to a superior because she feared retribution from fellow officers.

The hearing, called a trial board, is presided over by two police captains and an inspector. Picciano, whose job included escorting motorcades for the president, vice president and other dignitaries but who is now on desk duty, is expected to testify Thursday. The proceedings are providing the first detailed accounts of a case that embarrassed D.C. police and made international news.

The U.S. Secret Service and the U.S. attorney’s office ended a criminal investigation without filing charges. Officials told The Washington Post in September that authorities concluded Picciano, a 17-year veteran, was not serious. But administrative charges are different, and questions include whether the officer was derelict in his duties and exhibited conduct unbecoming a police officer.

The trial board panel is expected to issue its findings within two months. D.C. Assistant Attorney General Kevin J. Turner told members, “There is no place on the MPD for anyone who issues a threat, sarcastically or otherwise, while in uniform and in a public place.”

Turner said the Secret Service uncovered other troubling statements attributed to Picciano, including his Facebook page from 2009, on which he posted that he “felt like taking a rifle to a tall building.” Turner said Picciano was angry at the D.C. Council for curtailing pension benefits. In addition, Turner said Picciano referred to himself as the “zoo keeper of the MPD” on his Linked­In page.

The officer’s attorney, James W. Pressler, noted that the Facebook posting was old. The officer retracted it the same day, writing, Pressler said, that he “felt like it, but he would never do something like that.” The zookeeper comment, Pressler said, was a way of describing the workplace, and not as Turner suggested, to mind the animals living in the city.

One panel member, Capt. Mark Beach, said the internal- affairs investigation fell short. He quizzed the lead detective, Agent Brad Wagner, as to why he didn’t investigate the Facebook post by examining whether Picciano owned a rifle or by searching his home and vehicles. Wagner said the Secret Service seemed satisfied that there was nothing more to it and that the posting didn’t present an imminent threat and was protected speech on a private Internet chat with friends.

Authorities said the Obama incident occurred the morning of July 11 at Jack’s Fresh restaurant at 20th and L streets NW. Picciano was eating breakfast with three colleagues and was later joined by Officer Leslie Clark and her partner.

Testimony indicated that the conversation turned to heavy traffic during a recent escort for Michelle Obama and then about her threat level. An officer at the table explained that “a lot of people want to kill her.”

Clark, a 24-year veteran still with the special operations division, said she expressed surprise at that statement, and Picciano said, “Yeah, because I want to kill her.” Clark said she twice asked if he meant it, and that he said yes, and then showed her the picture of the gun on his phone.

Pressler and another officer gave a different account, saying that Clark asked who would kill the first lady. Picciano answered, “I guess I would.” At that moment, Picciano was talking with a colleague about a birthday gift of a .40-caliber handgun, and he was calling up a picture of it on his smartphone. The other officer said the picture came up just as Picciano made the comment about Obama and was handing the phone across the table to the other officer, Pressler said.

Clark said she quickly changed the subject to the Washington Redskins. She said she didn’t confide in her partner that she was troubled by what she heard and contemplated the repercussions of making a complaint.

Pressler said his client has gone through a “living hell,” and he accused top police commanders of leaking Picciano’s home phone number to reporters. “There was no threat,” the attorney said. “The officer made a sarcastic comment in response to a question made to him.”

Pressler asked Clark about her statements to the Secret Service, in which agents asked if she felt the threat was real: “I don’t know. But I don't trust nobody,” she told the Secret Service.

But to Pressler, she said, “I don’t know what he thinks. To me, it was a threat.”