A Black student in Pennsylvania was starting his graduation procession when he was told to remove his face mask displaying the words "Black Lives Matter."
The student, Dean Holmes, 18, was allowed to continue in York Catholic High School's procession last week after complying.
But his father contends in a lengthy Facebook post that the demand to remove the mask put his son at risk of the coronavirus and discriminated against him based on his race and prior civil rights activism at the school. "One can only graduate from high school one time and for him to have to suffer this injustice is reprehensible," John Holmes said in his post.
The high school in the city of York, about 100 miles from Philadelphia, said in a statement posted on its website Sunday that it was following a tradition barring messages on caps or gowns at graduation ceremonies.
"Any graduate wearing a cap, gown, or mask with any message would have been asked to remove it," the statement said.
The father said in his account posted to the Facebook page of Dean's mother on Saturday that the school did not issue any specific guidelines defining what would be an "unacceptable" mask or clothing prior to the ceremony.
In a telephone interview Tuesday, John Holmes said his son said he was wearing the Black Lives Matter mask during the practice before the official ceremony began, and that no one from the school said anything about it at the time. He noted that his son's Facebook page has pictures of him wearing his mask under his shield, which the father said were taken before the procession.
But after the actual procession began Dean was pulled from the line by a school official and forced to remove the mask, John Holmes said in the Facebook post.
"As a parent I will not stand for my son being humiliated publicly, having his basic human dignity crushed on what should have been one of the happiest days of his young life," the father wrote in his post. He said Dean will be attending New York University in the fall and majoring in economics.
The school in its statement said each graduate was given a face shield to be worn in lieu of a face mask. "Graduates gathered outside the church prior to processing inside" for the ceremony, the statement said. "They were checked in, asked several questions regarding exposure to COVID-19, and temperature checked."
The statement also disputed the father's contention that his son had the mask on prior to the procession.
"It was not until the last minute, right before entering the church, that the face mask with writing was put on," the statement said.
"We wish to re-emphasize that York Catholic believes in the dignity of all human persons, and the equal treatment of all people," the school's statement concluded. "We encourage our students, faculty, and alumni to engage in personal conversation, continue to listen with open hearts, always strive for better understanding, and grow as a supportive community of love and respect."
The father said in Tuesday's interview, however, that he believes the school's demanding his son remove the mask was in part due to Dean's prior activism on civil rights at the high school.
"My son started the minority student's club because he was specifically not allowed to call it the Black student union," the father said Tuesday.
John Holmes also said he has talked to school officials about the need for the school to have Black teachers among its staff, which he said is entirely white.
In response to a request for comment on Holmes's assertions, including on the racial breakdown of the teaching staff, a school spokeswoman directed NBC News to the statement on its website.