(CNN) — During evening rush hour in New York City on Monday, a man calmly walked into a Park Avenue office building lobby and killed a police officer, then opened fire on other innocent strangers.

After a deadly shooting at an NYC building that housed NFL and Blackstone offices, safety experts say it’s high time ...

Officer Didarul Islam, 36, who was guarding the building on a paid security job when he was killed, had served as a police ...