Maryland’s prison system is short several hundred correctional officers.

The American Federation of State, County and Municipal Employees union called on the state to fix the problem at a news conference Thursday morning at the Dorsey Run Correctional Facility in Jessup. Union leaders say the shortage endangers correctional officers.

According to the state Department of Public Safety and Correctional Services, there are about 600 corrections vacancies.

Department Director of Professional Standards Gary McLhinney said that’s a problem, but a tough one to fix. Of the more than 4,000 applicants tested since January 2015, fewer than 400 got the job.

“We’re not seeing people that can pass the polygraph examination,” McLhinney said. “And I can’t give a whole lot away, but they’re tested on things like prior drug usage, prior criminal involvement.”

But AFSCME Maryland President Patrick Moran said that’s not good enough.

“We know the department is hiring,” he said. “They’re just doing a very bad job of hiring officers.”

He suggested the state offer higher pay to attract stronger applicants, or cast a wider net in its recruitment efforts.