Family and friends gathered at Central Synagogue to mourn Wesley LePatner, one of four victims killed in Manhattan office building shooting this week.

New York City Police Officer Didarul Islam, killed in Monday’s mass shooting inside a Park Avenue skyscraper, was mourned at a funeral Thursday in the Bronx where thousands of cops from the NYPD and across the US flooded the streets.

Shane Tamura killed four people at a Manhattan office building Monday, including Blackstone executive Wesley Lepatner and New York City police officer Didarul Islam. The head of the NYPD said investigators plan to question a man who supplied parts for the gun that was used in the attack.

Officials said the gunman fatally shot himself after his attack, which set off a chaotic scene that rippled out into the heart of Manhattan during rush hour.

A vigil will also be held Friday night for NYPD Officer Didarul Islam so the community can come together in mourning. CBS News New York's Christina Fan reports.

Mourners packed a New York mosque to honor a Bangladesh-born police officer who was killed at an office building this week.