JACKSON, Miss. — In 1982, Christopher B. Epps, a young schoolteacher, took a second job as a guard at the facility known as Parchman Farm, the only prison operated at the time by the Mississippi Department of Corrections.

Eventually he had to choose a path. “It worked out that I was making more as a correctional officer than as a teacher,” Mr. Epps would later recall in an interview for a corrections newsletter.

By the time he spoke those words in 2009, Mr. Epps was being feted as Mississippi’s longest-serving corrections commissioner. The state inmate population had quadrupled, five private prisons had been built to help house them, and, according to a federal grand jury indictment, Mr. Epps had found a new, secretive way to bolster his income.

The 49-count indictment, unsealed last week, accuses Mr. Epps of receiving more than $1 million in bribes from a former Mississippi lawmaker named Cecil McCrory, beginning in 2007. In exchange, the indictment charges, Mr. Epps helped secure lucrative corrections department contracts for private prison companies owned or represented by Mr. McCrory.