Prince George’s County State’s Attorney Angela Alsobrooks, right, greets a spectator of a parade in Seat Pleasant on May 5. (Bill O'Leary/The Washington Post)

PRINCE GEORGE’S COUNTY — Maryland’s second-most-populous locality, with nearly 1 million people — suffered through an agonizing upheaval in 2010 when its highest elected official, notorious for pay-to-play politics and showering his allies with public funds, was nabbed on federal corruption charges.

Thanks to eight years of competent leadership since then under County Executive Rushern L. Baker III, the county has patched its reputation and achieved a measure of economic dynamism that had been lacking in one of the nation’s wealthiest majority-minority jurisdictions. The best way to sustain the county’s trajectory following the departure this year of Mr. Baker, who is running in Maryland’s Democratic gubernatorial primary, is to elect a serious, substantive, hands-on county executive with a track record of insisting on high ethical standards. Fortunately, there is a strong choice to fit that bill in the June 26 Democratic primary for county executive: Angela D. Alsobrooks.

As state’s attorney for Prince George’s for the past eight years, Ms. Alsobrooks has been the county’s top prosecutor. She has done an outstanding job. On winning election to the job in 2010, she inherited an office known for underpaying a badly overworked staff and mishandling a number of high-profile cases — embarrassments that raised questions about management in a critical agency.

Under Ms. Alsobrooks’s steady leadership, the office, with more than 200 prosecutors and support staff, has been rebranded and upgraded to such an extent that it is now widely admired as among the best in Maryland. Ms. Alsobrooks — focused, fearless, far-sighted — has been largely to credit for that turnaround, and for serious, innovative initiatives to combat domestic violence and predatory gangs. She is famously collegial, responsive, diligent and detail-oriented, widely admired in local law enforcement and beyond.

Ms. Alsobrooks’s experience as a prosecutor has given her broad expertise on the county’s complex social challenges and informed the agenda she has formulated for the job of county executive. She would be a strong advocate for a still-struggling school system and for preparing small children for kindergarten and high school students for college and careers. She has a matchless grasp of public-safety programs and how to improve them, and she would be proactive in supporting local businesses and pushing workforce training.

She has been attacked, outrageously, by labor unions backing her main primary rival, Donna F. Edwards, for “pay-to-play” politics, because she has accepted some campaign donations from developers. It’s a preposterous charge; in fact, Ms. Alsobrooks has an unblemished ethical record, and her donor base includes nearly 5,000 contributions from individuals, most of them county residents.

Ms. Edwards, a former congresswoman who lost a U.S. Senate primary race two years ago, is a formidable candidate; no one questions her intellect or resolve. However, she lacks Ms. Alsobrooks’s talent for collegiality, as well as her sense of accountability — in the House of Representatives, her office was notoriously unresponsive, and just a handful of her several dozen colleagues in the Congressional Black Caucus backed her Senate bid.

In Prince George’s, where voters are overwhelmingly Democrats, the primary winner is a shoo-in to win the general election. Based on her record, skills and intellect, Ms. Alsobrooks would make an outstanding county executive.