Last August, O'Hara admitted to taking pictures of two female lifeguards in their bathing suits while working as a lifeguard at Robert Moses State Park.
He publicly apologized and said he had taken the photos to raise awareness about the lifeguards' lack of official uniforms.
The state probe found the allegations of any wrongdoing could not be substantiated.
A second investigation by the district reached a similar conclusion.
"The district council's review of this matter in interviews with lifeguards and lifeguard supervisors by its investigators revealed no additional information to refute the state's determination," Islip Board of Education Vice President Paul Austin said at Thursday night's meeting.
Despite clearing O'Hara, the board has not decided on his future.
He has continued to get paid by the district while working from home. Acting Superintendent Kathleen O’Callaghan said O'Hara is been consulted on a weekly or bi-weekly basis but did not provide any specifics.
Frustrated parents spoke out at the meeting, demanding clarity on the situation. Many told the board they would not support a vote to bring O'Hara back to the district.
"If situations like this occur you have to remove people like that because the kids are the most important things that you have to really look out for," Islip parent Herman Ouffre said.
Others said they would respect the outcome of the investigations.
"I mean I think everyone deserves a second chance at anything," one Islip parent said.
"Listen if there's no wrongdoing you know, they made the decision and I support them," Islip parent Christine Rudner said.
Board members said a decision on O'Hara's future would be made "very soon" but offered no specific timeline.
The Islip Board of Education's next regular business meeting is scheduled for Monday, Feb. 10 at 7:30 p.m.