I went through that when I was teaching at a college. I caught some students cheating by copying each other’s work and putting their names on it. It just happened to be a class in PowerPoint presentations. I could hold the papers up to the light and see that a group of them were exchanging work to pass it in. The only thing different was the names on the papers. It is almost impossible to place images on a presentation slide in the exact same place with the exact same rotation & etc. I had to justify to the dean of students giving them zeros for the assignments and Fs for the class. The thing that saved my hide was that the student handbook had rules against plagiarism.