BOSTON – A former United States Postal Service employee pleaded guilty in federal court today to charges stemming from his involvement in a drug conspiracy.

Gerard Harrington, 48, pleaded guilty to one count of conspiracy to possess with intent to distribute and five counts of possession with intent to distribute and distribution of cocaine. Harrington, along with co-conspirators John Thibedeau, William Zuluaga and Sean Williamson, were indicted in September 2011. Harrington and Williamson are former Postal Service employees who worked out of the Somerville Post Office.

At today’s plea hearing, the prosecutor told the Court that the government’s evidence included video and audio recordings of the four co-conspirators conducting their drug transactions beginning in May 2011, and continued on at least five different occasions through Sept. 30, 2011, the date of Harrington’s arrest.

Judge George A. O’Toole Jr. set sentencing for June 12, 2012, at 3:00 p.m. Harrington faces up to 20 years in prison to be followed by at least three years of supervised release, and up to a one million dollar fine, on each count.

U.S. Attorney Carmen M. Ortiz and Rafael Medina, Special Agent in Charge of the United States Postal Service, Office of Inspector General, Northeast Area Field Office, made the announcement today. The case is being prosecuted by Assistant U.S. Attorney Eugenia M. Carris of Ortiz’s Public Corruption and Special Prosecutions Unit.