New York Times reporter Benjamin Mueller was in a hallway of a Bronx housing project. He was watching its residents mop up the blood of a 59-year-old woman who had been murdered days before.

“I mean, they’re sobbing, they’re screaming,” Mueller said. “It spoke to the way these people are often living the aftermath of murder in a shadow and very few people in New York City are paying much attention — in city government or the media. And these are the kinds of scenes you miss if you do the single day crime stories.”

Pieces of evidence are marked at a crime scene on Arnow Place near Westchester Avenue in Pelham Bay, the Bronx (Mike Albans/NY Daily News Archive via Getty Images)

The grim scene informed the first of a series of stories he and veteran Times law enforcement reporter Al Baker and others wrote titled “Murder in the 4-0,” an immersive examination of homicide in New York City’s 40th precinct.

On this week’s episode of The Breakthrough, Baker and Mueller describe how they gained the trust of skeptical police, fearful residents, and grieving relatives. They show how New York law enforcement struggles to bring down crime in this troubled corner of the city, even as it declines elsewhere.

Their work paid off. On Wednesday, the New York Police Department announced it would assign 75 new investigators to the Bronx.

Listen to Baker and Mueller on iTunes, Soundcloud or Stitcher.

Have an idea for the Breakthrough? Send us your suggestions — including which reporters we should talk to — at [email protected].