WASHINGTON — The federal prison population has dropped in the last year by roughly 4,800, the first time in several decades that the inmate count has gone down, according to the Justice Department. In a speech Tuesday in New York City, Attorney General Eric Holder said the Justice Department expects to end the current budget year next week with a prison population of roughly 215,000 inmates. It would be the first time since 1980 that the federal prison population has declined during the course of a fiscal year.

In addition, internal figures from the Bureau of Prisons show a projected drop of more than 2,000 inmates in the next year, and nearly 10,000 in the year after.

“This is nothing less than historic,” Holder said, addressing a conference at the New York University School of Law that was hosted by the Brennan Center for Justice. “To put these numbers in perspective, 10,000 inmates is the rough equivalent of the combined populations of six federal prisons, each filled to capacity.”

With policies that have at times unsettled prosecutors and others in law enforcement, Holder has worked in the last year to reduce a prison population he says is costly and bloated. The Bureau of Prisons accounts for roughly one-third of the Justice Department budget, and the prison population has exploded in the last three decades as a result of “well-intentioned policies designed to be ‘tough’ on criminals,” Holder said.