The director of human resources for the Capitol Police left the department just before Memorial Day, marking the second time in a year that the long-criticized HR division lost its top official.

Police officials would not comment on whether Jennifer McCarthy left on her own or was dismissed, though department spokeswoman Sgt. Kimberly Schneider said the position has already been filled with an acting director.

But McCarthy’s departure comes at a time when officials are working to completely overhaul how the HR division works. It also highlights a long-running problem that McCarthy had been working to fix: poor retention.

Already, about 30 positions on the department’s administrative side are not filled, placing a heavy workload on employees. And, in addition to not filling needed positions, HR has developed a reputation among officers for poor service.

McCarthy took over as director on May 27, 2007, moving up from associate HR director to replace Jan Jones. Other top civilian officials stepped down last fall, including Chief Administrative Officer Tony Stamilio, after criticism from Members of Congress and the Government Accountability Office about the department’s finances.

The GAO issued its first report on the department’s administrative problems in 2005, which criticized the department’s use of overtime. Since then, the GAO has made 46 recommendations addressing a wide range of issues; on the HR side, GAO analysts found that the division lacked a cohesive plan for hiring and training.

“There were persistent problems,” said Richard Stana, GAO’s director of homeland security and justice. “I mean, year after year there were the same kind of problems — not knowing who should be trained or when and on what subject.”

That meant HR employees might not get trained in some areas at all. The result was uneven service: One officer said his insurance was mistakenly canceled for four months, and other officers had stories of lost vacation days and leave.

At a hearing a month ago, Stana and Capitol Police Chief Phillip Morse reported that significant progress had been made. HR officials had adopted a hiring policy, Stana said, and were working on a plan for training. Schneider said those initiatives will continue as planned, despite McCarthy’s departure.

But in an interview Monday, Stana said the report focused on the planning aspects of HR and not on individual problems. And HR has yet to complete its work force plan, so there’s no mechanism to measure whether any day-to-day improvements have been made.

According to officers, problems are still rampant. Capitol Police Labor Committee Chairman Matt Tighe said officers are frustrated with bureaucratic service. One of the most common complaints, he said, is delayed reimbursement for work-related expenses. And calls are often routed through several different people, making the whole process complicated, he said.

“Basically HR has increased drastically in size but still doesn’t successfully meet the officers’ needs,” he said. “It’s a hindrance rather than a help.”