It is carefully choreographed and deeply dreaded, an event the New York Police Department plans for, stands ready for every day: the laying to rest of an officer killed in the line of duty.

No matter the particulars or the cause of death, longstanding traditions and powerful symbolism govern the aftermath, all arranged by the department’s Ceremonial Unit. That unit oversees everything from the somber blue-and-black bunting that is hung at the officer’s precinct to the specially trained pallbearers on call for the funeral.

But among the first displays of police unity after a death in the ranks is what is known as the dignified transfer. The department moves the body from the Office of Chief Medical Examiner’s custody to a funeral home or place of worship.

The transfer on Tuesday that followed the killing of Officer Didarul Islam in a Midtown skyscraper was no different — a quiet show of blue unity outside a mosque in Parkchester, in the Bronx.

Reporters Maia Coleman and Wesley Parnell spent all Tuesday outside Officer Islam’s nearby home and were present to witness the minutes when officers began to arrive outside the Parkchester Jame Masjid. They reported what they saw.