Khaleel Cooper, 39, allegedly knifed 40-year-old Tamara Rowe in her chest and right arm during a domestic clash inside their unit on East 232nd Street near White Plains Road in Wakefield, authorities said. 

The suspect went postal inside the USPS' Midwood branch on Coney Island Avenue near Avenue I around 1:15 p.m., police said. 

Dominick Sabater, 23, of Harlem, allegedly sprayed the substance – held inside an 8.1 ounce container with an image of a bear on the label – as the crowd in the greenspace swelled to about 1,000 people around 7:50 p.m., authorities and law enforcement sources said.