According to Wikepedia Holyoke there seems to have a lot. Check it out:
http://en.wikipedia.org/wiki/Going_postalNotable postal shootings[edit]
Main article: List of postal killings
Edmond, Oklahoma in 1986[edit]
On August 20, 1986, 14 employees were shot and killed and six wounded at the Edmond, Oklahoma, post office by Patrick Sherrill, a postman who then committed suicide with a shot to the forehead.[3]
Ridgewood, New Jersey in 1991[edit]
A former United States postal worker, Joseph M. Harris, killed his former supervisor, Carol Ott, and killed her boyfriend, Cornelius Kasten Jr., at their home. The following morning, on October 10, 1991, Harris shot and killed two mail handlers, Joseph M. VanderPaauw, 59, of Prospect Park, N.J., and Donald McNaught, 63, of Pompton Lakes, N.J. at the Ridgewood, New Jersey Post Office.[4][5]
Royal Oak, Michigan in 1991[edit]
The U.S. post office in Royal Oak
On November 14, 1991 in Royal Oak, Michigan, Thomas McIlvane killed five people, including himself, with a Ruger 10/22 rifle in Royal Oak's post office, after being fired from the Postal Service for "insubordination." He had been previously suspended for getting into altercations with postal customers on his route.[6]
Double event in 1993[edit]
Two shootings took place on the same day, May 6, 1993, a few hours apart. At a post office in Dearborn, Michigan, Lawrence Jasion wounded three and killed one, and subsequently killed himself. In Dana Point, California, Mark Richard Hilbun killed his mother, then shot two postal workers dead.[7]
As a result of these two shootings, in 1993 the Postal Service created 85 Workplace Environment Analysts for domicile at its 85 postal districts. These new positions were created to help with violence prevention and workplace improvement. In February 2009, the Postal Service unilaterally eliminated these positions as part of its downsizing efforts.[8]
Goleta, California, in 2006[edit]
Jennifer San Marco, a former postal employee, killed six postal employees before committing suicide with a handgun, on the evening of January 30, 2006, at a large postal processing facility in Goleta, California.[9]
Police later also identified a seventh victim dead in a condominium complex in Goleta where San Marco once lived.[10]
According to media reports, the Postal Service had forced San Marco to retire in 2003 because of her worsening mental problems. Her choice of victims may have also been racially motivated; San Marco had a previous history of racial prejudice, and tried to obtain a business license for a newspaper of her own ideas, called The Racist Press, in New Mexico.
This incident is believed to be the deadliest workplace shooting ever carried out in the United States by a woman.[11][12]
Baker City, Oregon, in 2006[edit]
Grant Gallaher, a letter carrier in Baker City, Oregon, pleaded guilty to the April 4, 2006 murder of his supervisor.[13] He reportedly brought his .357 Magnum revolver to the city post office with the intention of killing his postmaster. Arriving at the parking lot, he reportedly ran over his supervisor several times. Subsequently he went into the post office looking for his postmaster. Not finding the postmaster, he went back out to the parking lot and shot his supervisor several times at close range, ostensibly to make sure she was dead. He then reportedly fired several more bullets into the supervisor's car.[citation needed]
Grant Gallaher reportedly was on a new route for three weeks and had felt pressured by a week-long work-time study and an extra 20 minutes added to his new route.[citation needed] On the day of his rampage, he reportedly was ahead of schedule on his route and his supervisor brought him more mail to deliver. He allegedly decided to take the matter up with his postmaster on his cell phone and then went home to get his .357 Magnum revolver to exact his revenge. The work climate had reportedly improved from what it was in 1998, the year a 53-year-old union steward at the Baker City post office committed suicide
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