A man stalked through a Manhattan office tower firing a rifle, killing four people, including a New York City police officer, and wounding a fifth before taking his own life, officials said.

Didarul Islam, 36, was fatally shot during Monday’s Midtown Manhattan shooting. Sources say the off-duty NYPD officer was married, and his wife is eight months pregnant.

The NYPD officer shot and killed by a deranged gunman inside a Midtown Manhattan skyscraper Monday was identified as a “hero” dad and nearly four-year department veteran – whose wife is about to