A history teacher took responsibility for painting over three murals in the halls of the Martha’s Vineyard Regional High School late last week, an incident that sparked widespread controversy.

High school principal Sara Dingledy confirmed on Monday that Andrew Vandall had admitted to obliterating the murals on the walls near classrooms where he and Elaine Cawley Weintraub taught. The incident followed close on the heels of Ms. Weintraub’s sudden retirement, announced two weeks ago amid blunt criticism of the school administration.

Ms. Dingledy described the incident as isolated but acknowledged the backlash, including on social media.

“We take it seriously too, this is a school community issue,” she said. “My biggest concern was the staff and students,” she added.

The murals in the hallway outside the history department classrooms had been painted by students through the years in connection with coursework taught by Ms. Weintraub. They included a female Irish sailor, a Brazilian timeline and a portrait of the African American female boxer Emma Maitland. The latter mural was painted last year by a graduating senior who won an award for it in the school’s annual Heritage Trail competition.

Speaking to the Gazette by phone Monday, Ms. Weintraub said she discovered the painted-over murals when she came to the school last Thursday to clean out her classroom.

“I have no idea why someone would do that,” she said.

In a statement emailed to the Gazette Tuesday, Mr. Vandall defended his action, noting that not all the murals were painted over.

“I did not intentionally want to destroy the previous cultural and ethnic artwork, as much still remains untouched and admired,” he wrote. “I wanted to enhance and continue the momentum of sharing to create spaces for current students to grow and show their cultural heritage.”

He also wrote: “If all the old artwork can never be changed, how do we provide current students with space to show their diverse interests and culture?”

Ms. Dingledy said the school had video footage from security cameras that confirmed the incident took place sometime Wednesday evening, June 14. The painted-over murals were discovered the morning of June 15, she said. She could not confirm reports that a second person was involved.

“I do know that there is one staff member that engaged with this, if there was anyone else, it was not someone affiliated with the school,” the principal said.

Citing the need for confidentiality in personnel matters, Ms. Dingledy could not say if Mr. Vandall would face disciplinary action for painting over the murals, but she did confirm that he broke a rule. There is a process in place for painting school walls, she said, and he acted without administration approval.

“The facilities manager manages the walls [and] manages what’s painted on the walls,” she said. “We absolutely take professionalism of teachers seriously,” she added.

Ms. Dingledy said high school staff gathered on Monday to discuss the incident. And said school administrators were working to set something up that would allow students express their reactions to the incident before the last day of school on Wednesday.

In an email that went out to parents early in the week , Ms. Dingledy wrote:

“As you know, student artwork was painted over last week in the 500s wing. Over the weekend, a teacher admitted to painting over the murals. This was done without administrative permission. We will address any further discipline directly with this staff member and with district administration.

“The teacher has sent a letter of apology to the staff and we processed this incident as a faculty. MVRHS will afford students the opportunity to process their feelings and ideas on how to move forward as a school on Wednesday or Thursday with our restorative counselors. We hope that this isolated incident by one individual does not eclipse the great work teachers are doing here every day. There is a great staff here that is fully committed to providing an excellent and inclusive education for all.”

Speaking to the Gazette by phone mid-week, Ms. Dingledy said she was sorry for the students that the incident had cast a shadow across the end of the school year — ordinarily a joyful time with graduation and summer vacation ahead.

“They are caught in the crossfire of an adult conflict, that I think is most unfortunate,” she said.