A former Moncks Corner police officer was arrested today after investigators said they uploaded child porn from his computer.

Robert Carlton Shirer, 44, of North Highway 17A in Moncks Corner, is charged with 20 counts of second-degree sexual exploitation of a minor, according to the S.C. Law Enforcement Division.

Investigators uploaded numerous files showing children engaged in sexual activities from Shirer’s home computer through a file-sharing network July 26, Aug. 27 and Oct. 3, according to the arrest warrants.

Shirer resigned from the force Monday, according to Chief Chad Caldwell. He didn’t say how long Shirer had been on the force.

Information about his record from the S.C. Criminal Justice Academy was not immediately available.

Shirer was arrested after an investigation that included SLED, the S.C. Attorney General’s Internet Crimes Against Children Task Force, the Greenwood (Ind.) Police Department and the Brevard County (Fla.) Sheriff’s Office, according to SLED.

Shirer is being held in the Berkeley County jail.

Reach Dave Munday at 937-5553 or twitter.com/dmunday.