http://www.civilrights.org/publications/hatecrimes/disabilities.html
Perhaps the biggest reason for underreporting of disability-based hate crimes is that disability-based bias crimes are all too frequently mislabeled as "abuse" and never directed from the social service or education systems to the criminal justice system. Even very serious crimes including rape, assault, and vandalism are too-frequently labeled "abuse."
In one of the few disability-bias cases successfully prosecuted, in 1999, Eric Krochmaluk, a man with cognitive disabilities from Middletown, N.J., was kidnapped, choked, beaten, burned with cigarettes, taped to a chair, his eyebrows shaved, and ultimately abandoned in a forest. Eight people were subsequently indicted for this hate crime making this one of the first prosecutions of a disability-based hate crime in America.
http://www.nytimes.com/1999/02/17/nyregion/8-are-charged-in-tormenting-of-learning-disabled-man.html
Apparently copying a horror movie, a pack of men and women living near the New Jersey shore enticed a man with learning disabilities to a party and then tormented him for almost three hours, the Monmouth County Prosecutor charged yesterday.
''It was just cruelty,'' said John A. Kaye, the Prosecutor. The abuse included whipping the 23-year-old, shaving his head and dragging him into the woods for further beatings, Mr. Kaye said.
Eight men and women were arrested Monday after a two-week investigation into the incident. Most of the defendants face kidnapping or assault charges.