Dear Rosalind,
I can understand your frustration with the cheating that happened among your students. I know it is very difficult to deal with. I remember once where I had a similar situation involving two of my Academic Writing Students and their final Written Paper. As I was reading the papers, I noticed that the words used, pictures used, and thoughts presented were identical in these two papers. As plagiarism is a very big issue within both University and Community College settings, I first brought the issue of the identical projects to my Department Chair and ESL Instructor Colleagues where we discussed the issue. Then, when I was returning the papers to the students the next day, I withheld the two identical papers and told those students that I needed to discuss their work with them as I had some questions I needed to be answered before I could assign a grade. I did not tell them I suspected they had cheated or copied each other. I arranged to meet with them the next day. Prior to the meeting, I asked some of my colleagues if they would also be present at this meeting, and they agreed. The students involved did not that the other faculty members would be present. At the time of the meeting, I was very cordial, and indicated the areas in the paper where I found the identical thoughts and words. I did not accuse the students involved of cheating. I expressed my concerns, and then allowed the students to save face (they were Hispanics) and say which one had copied from the other student. After the student who had copied had admitted their mistake, I indicated that the one who gave their work to be copied would receive one grade lower than they would have received, and the one who copied would receive a grade that was two grade lowers than what they would have received. They were very appreciative of this, and definitely learned a valuable lesson in the process.

Maybe this is something you might be able to propose with the other teachers during your meeting.
Dr. Yanni Zack