How about Jiverly Antares Wong?
From Wikipedia: The Binghamton shootings took place on Friday, April 3, 2009, at the American Civic Association immigration center in Binghamton, New York, United States. At approximately 10:30 a.m. EDT, a naturalized immigrant Jiverly Antares Wong (aka Jiverly Voong) entered the facility and shot numerous people inside. Fourteen people were ultimately confirmed dead, including the shooter, and four were wounded. The injured people, aged from twenty to mid-fifties, were treated for gunshot wounds at Wilson Medical Center in Johnson City and Our Lady of Lourdes Memorial Hospital in Binghamton.
See
http://en.wikipedia.org/wiki/Binghamton_shootings
The OP says that all the crazy shooters in the past 5 years have been Jews. I guess that means that Mr. Wong (Jiverly to his friends) was sane.
Oh, and there's the obligatory: "Another one of his coworkers stated, "He was quiet -- not a violent person" and "I can't believe he would do something like this." [from Wikipedia]