On Monday Butler County, and Western Pennsylvania in general, lost a key figure in the fight against opioid addiction and death, when U.S. Attorney David Hickton announced his resignation, effective Nov. 28

Mr. Hickton’s resignation wasn’t unexpected. U.S. Attorneys are appointed by the President and usually vacate their position when executive power shifts between parties.

That doesn’t lessen the import of his departure. Hickton, who liked to say “we can’t arrest our way out of this problem,” of opioid addiction and overdose deaths, emerged as a keystone of this region’s fight against heroin deaths.

Hickton’s tenure, which began in 2010, pivoted to heroin, opioids and other concerns after he pledged to take on environmental concerns, civil rights violations and mortgage fraud.

In 2011 he brought together police and community leaders in a working group to foster trust between law enforcement and residents — a prescient move given the fear and anger that would begin roiling many communities amid a national conversation about the use of force by police.

In 2014 Hickton pledged to crack down on health care fraud, recognizing that the region’s plethora of providers and aging demographics make it fertile ground for scammers seeking to bilk insurance companies and government programs out of service reimbursements.

In August, Hickton’s office won a hard-fought guilty plea from Nicholas Trombetta, founder of the Pennsylvania Cyber Charter School in Beaver County. The case, in which Trombetta admitted to siphoning $8 million from the school using a network of other entities he created, helped shine a light on Pennsylvania’s lackluster regulation and oversight of cyber charter schools.

Perhaps his crowning achievement was the release earlier this year of a 64-page report laying out a regional response to Western Pennsylvania’s opioid epidemic. The effort, developed with the help of dozens of regional experts and law enforcement officials, got Hickton tapped in 2015 to run a federal task force on the issue. He used the platform to focus national attention on how community awareness and treatment are often overlooked and underappreciated components of the fight against drugs. Paired with Hickton’s push for tougher penalties on dealers of fatal drugs, that is a potent combination.

Priorities and policies change as quickly as the name of the prosecutor leading the U.S. Attorney’s Office in Pittsburgh. That will undoubtedly be the case with whomever follows Hickton — just as it was when Hickton replaced U.S. Attorney Mary Beth Buchanan in 2010.

But confronting the scourge of heroin and prescription opioids requires an unwavering focus and commitment to the holistic approach Mr. Hickton championed. It’s incumbent on his successor to build on his successes, not abandon or roll them back.