Sandwich launched by protester reportedly shattered and left mustard stain on border agent, legal proceedings reveal

A federal customs official has stated under oath he could feel through his protective gear the impact of a food product thrown at him by a capital city activist, who has faced court proceedings for physical attack.

Federal border agent the government official told the legal jury the snack "exploded all over him" and he "detected the aromatic vegetables and yellow sauce" on his work clothing.

Both legal teams contests that the accused, 37, did in fact throw profanities and a deli-style sandwich at law enforcement deployed by the former president to secure the nation's capital in late summer.

The occurrence was recorded on camera and became popular online, making the accused a representation of protest in the federal district to Trump.

State lawyers originally tried to secure serious criminal counts against Mr Dunn, but a grand jury refused to charge him.

Trump's deployment of armed forces to Washington DC this summer generated protest from some of the city's residents, who viewed it as a partisan deployment of the armed forces.

Per charging documents, the defendant approached a group of officers at about 23:00 on August 10, describing them "authoritarians" and exclaiming: "Why are you here? Your presence is unwanted in my city!"

The court saw a demonstration from the agent on the trial day as he gave evidence against the defendant.

"I detected it through my protective gear," he testified of the sandwich's impact, adding that an onion string remained from his communication device and condiment discolored his clothing.

Mr Dunn's legal counsel, Julia Gatto, said in her initial argument that hurling the deli product was a "non-threatening act that did not, could not, result in harm".

But government attorney the prosecutor maintained the defendant must be considered responsible.

"Regardless of identity, you cannot simply launching items at people because you're mad," the attorney stated.

After the claimed attack came to light, Mr Dunn was dismissed from his job as a law firm employee in the Department of Justice.