I had exactly same experience before. The exam paper is copy paper with no prints, I graded with my comments. The student was so bold, he used a new paper to write down the correct answer, then he traced my comments using red ballpoint pen onto the new paper. However, I can tell it was not my handwriting, in addition, the red ink is not identical to mine. I kept his fabricated paper with me, and I told him that I will talk to the professor and let him know. Before I decided what to do with the situation, the student emailed the professor himself and cc'ed me, claimed that I graded his paper wrong, it was his mid-term exam, the score was very important to him. I showed the professor his fabricated paper, and other students' unclaimed paper that I kept, the professor stood on my side. Later, I had to attend a student and teacher discipline committee for this incident, they asked me if I graded all the paper at one time, or separate times, did I use the same pen for all the papers, did I know this student before, etc. Eventually I heard that student failed that class and it was his final term, he cannot graduate that semester.
学生发给我试卷截图，我99.99%确定他在我改卷之后篡改了自己的计算过程。为什么那么肯定呢？因为他漏改了某个中间步骤。。。根据他原本错误的计算，频率用的是6.5，我阅卷后他改成12.5，所有carry on的计算都用了这个值。唯独漏了一处，莫名其妙跑出来一个6.5。。。然后我再仔细看看别的地方，的确有橡皮擦后再写上去的痕迹。他能钻空子是因为这道题需要看曲线毛估估数值，所以我即便在一旁写了，“不对，根据你的计算应该是13，不是6.5”，他argue说，没，我估算的是12.5，完全合理，你批错了。
现在问题是我该怎么处理，是直接告诉教授嘛？我们有的作业要写些小程序，有的学生会抄袭，但这事系里、教授那儿都不怎么管。因为“没有明确的证据说明学生抄袭作业”。同样监考也是，看到有学生在那里“眉来眼去”，也没办法说是作弊，因为没有“solid evidence”。所以我觉得汇报给教授也会不了了之。可这件事情真的让我很不爽，我这门课教过近10个学期了，这种不诚实胆子又大的事情我第一次碰到。而且，这人当我是弱智么。。
麻烦大家帮我出出主意，我是正面和学生忿，还是交给教授处理，该怎么说／写邮件？谢谢啦！！！
学生现在敢这么对付，就是没有把你放在眼里。有可能后来会搞得ugly，你就得跟教授提前打好招呼。我会觉得跟教授面谈比email要好，不过一定要把来龙去脉说清楚。
所以后来拿到试卷第一件事所有试卷scan一下。
现在你需要告诉教授 他如果不作为是他的选择 但是你不说出了事就是你的问题了
我准备以后头上戴个go pro改卷子。。
你的事情，先别理学生，问问老师怎么办。十有八九老师无所谓
我的规定是出了教室门就不能regrading 了
天呐，如果400人的大课，扫到什么时候啊？
大半夜的被这句话笑出声了 ---发自Huaren 官方 iOS APP
那是批考卷还是做矿工。lol
州立大学的美国本科生，硕士生，特别是非理科的，有那么一群，那真是。。。一言难尽。。。
最地道的美国式做法：直接交给教授处理。要有书面文件。书面文件要注意言辞。
这样的事情我非常有经验，Do not take it personal. Treat it professional. 希望mm能看到。
I had exactly same experience before. The exam paper is copy paper with no prints, I graded with my comments. The student was so bold, he used a new paper to write down the correct answer, then he traced my comments using red ballpoint pen onto the new paper. However, I can tell it was not my handwriting, in addition, the red ink is not identical to mine. I kept his fabricated paper with me, and I told him that I will talk to the professor and let him know. Before I decided what to do with the situation, the student emailed the professor himself and cc'ed me, claimed that I graded his paper wrong, it was his mid-term exam, the score was very important to him. I showed the professor his fabricated paper, and other students' unclaimed paper that I kept, the professor stood on my side. Later, I had to attend a student and teacher discipline committee for this incident, they asked me if I graded all the paper at one time, or separate times, did I use the same pen for all the papers, did I know this student before, etc. Eventually I heard that student failed that class and it was his final term, he cannot graduate that semester.
以后拿相机手机在卷子里随机抽一部分拍照，告诉学生你有copy, 他们不敢随便改。发完试卷收回来，不让带回去。
我脑补了下头戴go pro改卷子的景象。。笑死我了