NBCNewYork.com
Authorities said postal worker David Barnett attacked a colleague in a case of work rage at a JFK mail sorting facility.
A disgruntled postal worker didn't like how his boss ran things, so he took out a pair of scissors and attacked, police said.
Though co-workers told investigators that they saw no signs of pre-attack distress in Barnett, he admitted thinking about killing his supervisor since October, police said. He gave officers both verbal and written statements describing the provocations, saying he had two issues with her this week alone -- one dispute being over a time card, according to cops.