A D.C. judge dismissed a gun possession case amid questions over whether the arresting officers wore or had any role in the creation of a controversial T-shirt printed with the name of their police unit, an image of the Grim Reaper and a symbol that an advocacy group says is racist.

The decision came Tuesday as the trial was set to begin for 24-year-old Carlos Johnson, who allegedly was found carrying a 9mm handgun last December. He had previously pleaded guilty in a case of assault with a dangerous weapon, a case that involved a gun.

D.C. Superior Court Judge Maribeth Raffinan rejected a request by prosecutors to delay the trial until an internal police investigation into the T-shirts has been completed. The judge dismissed the case without prejudice, meaning authorities can recharge Johnson.

The dismissal marks the first time the T-shirt is known to have had an impact on a criminal case.

The T-shirt came to light last month after an officer on the Powershift team in the 7th Police District was seen wearing it at a restaurant and in D.C. Superior Court. Police officials pronounced it “disturbing,” suspended that officer and opened the internal investigation.

The two officers involved in Johnson’s arrest are members of the same Powershift unit, which patrols high-crime areas for weapon recovery and drug activity.

On July 30, the day before Johnson’s trial was to begin, prosecutors sent an email to the defense saying it was “possible” that one of those officers had a role in designing the shirt. In the email, which was included in the court file, prosecutors called the information “hearsay” and said they were investigating the allegation.

In court hearings that stretched over Monday and Tuesday, Assistant U.S. Attorney Kate Rakoczy told the judge that it was unclear whether either of the officers involved in Johnson’s case had worn the T-shirt. But to make sure, she wanted to wait until police completed their inquiry.

“The government very much wants this matter to be thoroughly and effectively investigated so MPD can make the decisions it needs to make about what’s appropriate so that we can decide what to do with this information with our own cases,” Rakoczy said, according to a transcript of the proceedings.

Making the Johnson case more challenging, Rakoczy told the judge, was that officers in the Powershift unit have consulted attorneys who advised them not to discuss the T-shirt. She asked that the Johnson trial be rescheduled to October.

Johnson’s attorney, William Alley, of the Public Defender Service, opposed a delay. He indicated that he wanted to determine whether there was any bias against Johnson, who is African American, and sought to have the officers questioned about the meaning and origin of the shirt, according to court documents and transcripts of the proceedings.

At one point, Alley suggested that prosecutors could ask the officers “what they know about this investigation, about this T-shirt, who was involved, who designed it, who owns it, who wears it and provide all that information to us today so that we could be ready to move forward with trial.”

Raffinan considered delaying the trial for a few weeks, but prosecutors said that would not be enough time. The judge said that waiting months for the T-shirt investigation to wrap up would not be fair to Johnson, who had been jailed awaiting trial.

“I don’t think that lengthy of a continuance so that the investigation can be concluded, in exercising my judgment, is fair, equitable in these circumstances,” Raffinan said.

The black T-shirt has the Grim Reaper as its centerpiece, holding what appears to be a rifle with the District of Columbia flag attached. At the top is the word “Powershift,” with a pre-Christian style of cross embedded in a circle.

There are various interpretations of that symbol. Several hate groups have appropriated the cross as part of their symbology. It also appears in the lettering of a popular computer gaming company, and some have suggested it might represent the crosshairs of a gun scope.

Law for Black Lives, a group of legal professionals affiliated with the Black Lives Matter movement, filed the formal police complaint after an officer was seen wearing a shirt with the symbol. In its complaint, Law for Black Lives said the cross symbol was adopted by the Ku Klux Klan and “promotes white supremacist ideologies.”

On its website, the Anti-Defamation League lists the cross as a commonly used white supremacist symbol.

Mark Pitcavage, a senior research fellow with the Center on Extremism for the ADL, said he also noticed that much of the writing on the shirt is in a font called Exocet Medium, in which the letter O “is rendered with a cross inside it.”

Pitcavage said it is “highly likely” that “the only reason that image appears on the shirt is as a byproduct of the font selected.”

The image on the T-shirt also includes a police badge and the phrase, “Let me see that waistband jo,” an apparent reference to “jump outs,” a long decried, and police say now defunct, practice of police jumping out of cars to round up people. Others who have seen the shirt say the “jo” is mocking a slang expression used by some black youths in the neighborhoods where the units focus.

Former prosecutor turned defense attorney Justin Dillon said it is likely that defense attorneys in other cases involving the 7th District Powershift unit may seek details about the shirts.

“They’re trying to figure out if any of these officers are racists,” Dillon said. He said it is unclear whether a judge would allow questioning about the shirt in front of a jury. Attorneys would also have to prove that the officer knew the symbol was racist.

Dustin Sternbeck, the chief spokesman for the D.C. police department, said nine officers are assigned to the 7th District’s Powershift, which generally works at night and patrols some of the city’s most violent areas, including Anacostia, Barry Farm, Naylor Gardens and Washington Highlands. One of the officers, the person who was the subject of the complaint, is on desk duty and barred from having interactions with the public.

In an interview Friday, D.C. Police Chief Peter Newsham said the investigation “will find out what happened here. Was it was one officer, more than one officer, supervisor problems?” Police said the inquiry must be completed within 90 days.

Newsham cautioned against reading too broadly into the dismissal of the gun case, saying it does not necessarily indicate the potential for more cases to be affected. The chief called the government’s request for a delay reasonable and said the judge denied it “without any consideration for the impact on public safety.”

Newsham said the ADL had briefed the department on possible interpretations of the cross. But he said that even without the cross, he finds the T-shirt inappropriate attire for an on-duty police officer.

“Any shirt that causes a rift with the community is a problem for me,” Newsham said. “It’s poor judgment, at the least. Most of our officers on a daily basis exercise very good judgment under very difficult circumstances.”

Officials with the U.S. Attorney’s Office and the D.C. Public Defender Service, and Raffinan, the judge, declined to comment.

A representative from the police union also declined to comment. Neither the officer who is the subject of the police complaint nor the officers involved in Johnson’s arrest could be reached for comment.

Magda Jean-Louis contributed to this report.