A Warren County man who pleaded guilty to federal charges of producing and transporting child pornography has been sentenced to more than 28 years in prison for the crimes.

Randall P. Abernathy, 36, Wright City, was sentenced Wednesday by U.S. District Court Judge Catherine D. Perry to 339 months for the offenses.

Abernathy pleaded guilty in January to engaging in the illegal activities between September 2010 and September 2011, according to the U.S. attorney’s office.

The case was investigated by the FBI.

Previously, Abernathy was sentenced to 125 years in prison on Warren County charges of sexual exploitation of a minor; promoting child pornography in the first degree; and first-degree statutory sodomy.

St. Charles Circuit Judge Nancy L. Schneider sentenced Abernathy in the Warren County cases.

The Warren County Sheriff’s Department in September 2011 began investigating a case of alleged sexual exploitation of a juvenile female.

When the investigation began, the girl was 11 years old, according to court records.

An investigator with the sheriff’s department was provided with a cellphone which belonged to Abernathy containing nude and sexually explicit photographs of the victim.

The photographs were taken at a home off Apache Drive in Warrenton, the sheriff’s office reported.

During an interview with authorities, Abernathy made several statements with regard to taking nude photographs of the victim since she was 10 years old, according to a probable cause statement.

Abernathy would exchange the photographs for other photographs, the sheriff’s office stated.

He also told investigators that he would take 10 or more photographs at a time on at least three occasions.

Abernathy added that there were more than 20 photographs taken, but fewer than 60, according to the probable cause statement.

Donya Jackson, a criminal investigator with the U.S. attorney’s office, viewed Abernathy’s email account and confirmed he had sent pornographic images of a minor female electronically, according to reports.