Constance Miller, a high school graduate in Mississippi who sought to bring her girlfriend to her prom, was sent to a decoy prom with several students with learning disabilities. She had sued the school to let her attend prom and won, albeit the judge did not or was legally unable to force the school to allow her and her girlfriend to attend. It appears that parents and the school conspired to hold a decoy prom for the "different" students, while they held a real prom elsewhere for the "normal" students.
This incident is not criminal, but it is basically a hate crime in all other respects.
The author of the article links this Constance's treatment to bullying, which is a major public health problem in schools. She links readers to the Human Rights Campaign's diversity guide for schools, and mentions two anti-bullying bills that have been introduced in the House that HRC will likely support.