The police officers and residents of the Bangladeshi enclave stood in solemn witness for hours, blanketing the street outside the Bronx mosque in a sea of somber respect for Didarul Islam, 36, an officer slain by a gunman in the heart of New York.

The speeches and prayers recalled the heroism and honor of a fallen officer, but also the generosity and humanity of a father, a son and a leader in the community.

And just as the service was about to end, the skies opened up, drenching dress uniforms and kurtas, a release after days of stifling heat and grief.

The funeral, held in the Parkchester Jame Masjid, on a residential street in Mr. Islam’s Bronx neighborhood, came three days after Mr. Islam was killed in the city’s deadliest single shooting in 25 years.

The shooting broke out on Monday, when a gunman entered an office building at 345 Park Avenue carrying an assault-style rifle and began shooting, killing Mr. Islam and then two others. He then headed to the 33rd floor, where he killed a fourth person and then took his own life. The attacker, who had traveled across the country from his home in Nevada, had intended to target the headquarters of the National Football League, the authorities said.

The funeral drew hundreds of police officers from at least 54 of the city’s 77 precincts, and more still from neighboring states and counties. It transformed the quiet neighborhood.