If you live in Brooklyn, Buffalo, or Long Beach, you might have heard it lately: the clatter of jackhammers as utility workers replace gas lines under the street. The process can drag on for months, as workers dig up roads and sidewalks and drill into homes to swap out aging metal pipes for new, plastic ones.

In a state with one of the oldest natural gas networks in the country, replacing “leak-prone” pipes — steel or iron gas mains sometimes more than 100 years old — is a colossal task. And it’s not cheap: For most of the state’s major gas utilities, replacing these rusty pipes is the single biggest item driving infrastructure spending. Con Edison alone aims to spend close to $600 million a year over the next three years on this effort — one of the many expenses behind its current request to state regulators for double-digit rate hikes.

Over the coming decades, while New York is legally required to decarbonize nearly its entire economy, utilities are planning to sink tens of billions more dollars into replacing old gas mains, according to a new study by the climate think tank Switchbox. That’s despite the fact that, in some cases, it would be cheaper to remove them and install cleaner alternatives for every customer they serve.

Throughout the 1990s, favoritism ran rampant in New York City’s court system: Political leaders within the boroughs were getting state Supreme or Surrogate’s Court appointments from the same judges they’d helped elect.

These appointees are charged with managing the finances of New York’s most vulnerable populations — widows, children, and people with cognitive disabilities — and are paid from the same funds they’re managing.

On Wednesday, New York Focus examined how political patronage never left this appointment system, despite reforms implemented two decades ago by then-Chief Judge Judith Kaye.

When lawyers are appointed by judges based on connections, not competence, clients may be forced to pay for less than stellar representation. And when a politically connected lawyer is appointed, and appears before the same judge for their client, it can raise other parties’ suspicions in the case.

Here are four key takeaways from our investigation.

There are perhaps hundreds of innocent people in New York prisons. Studies estimate that as much as 6 percent of the US prison population is wrongfully incarcerated — that translates to roughly 2,000 wrongfully incarcerated people in the state. Their path to exoneration is narrow: They can appeal their convictions in court, but New York appellate courts rarely grant full exoneration.

Over the past decade, New York prosecutors have been promoting conviction integrity units, commonly known as CIUs, as an alternative path to exoneration. For incarcerated people who’ve exhausted their court appeals, the units are often their last resort.

These specialized departments, typically housed within DAs’ offices, are tasked with re-examining wrongful conviction claims. They promise a fair and independent review, a collaborative fact-finding mission.

New York Focus, in collaboration with Columbia Journalism Investigations, recently published the first installment of an investigation into CIUs and how they operate.

Over the course of a year, we reviewed every known exoneration case in New York counties with a CIU. We interviewed more than 100 exonerees, defense attorneys, legal scholars, current and former CIU staff members, and elected district attorneys in order to evaluate the units’ efficacy.

Here’s what we found.