David McAnally, 64, of Mars will spend four years in prison for possessing more than a half-million pieces of material depicting the sexual exploitation of young girls.

U.S. Attorney Scott W. Brady on Friday announced the sentence, which was imposed in the U.S. District Court for the Western District in Pittsburgh by Senior Judge Nora Barry Fischer.

McAnally was also sentenced to eight years supervised release after serving his imprisonment.

Information presented to the court states that McAnally on Sept. 4, 2015, was found to possess more than 500,000 still images and videos in computer graphics files that depicted minor females, some younger than age 12, engaging in sexually explicit conduct, according to a news release from Brady.

McAnally received and distributed the images through Bit Torrent, a peer-to-peer Internet file-sharing network, the release said.

Pennsylvania State Police conducted the investigation as part of Project Safe Childhood, a nationwide initiative launched in May 2002 by the U.S. Department of Justice to “combat the growing epidemic of child sexual exploitation and abuse,” said the release.