Subscribe | UPI Odd Newsletter Subscribe PORTLAND, Ore., Oct. 1 (UPI) -- A former mail carrier in Oregon has been sentenced to 18 months in jail for selling marijuana while on the job. Ronald Richard Berkan, 48, was given the jail sentence, which is scheduled to begin in December, after he pleaded guilty to distribution of marijuana to an underage person, The (Portland) Oregonian reported Wednesday. Advertisement His arrest followed an 11-month investigation by the Drug Enforcement Administration and the Office of Inspector General of the U.S. Postal Service that was launched after a bartender reported a uniformed mail carrier selling marijuana in 2006. Berkan, who resigned from the Postal Service after pleading guilty in April, was videotaped via a camera planted in his mail truck. Investigators said Berkan appeared to sell marijuana to 10 people on the tape, but the video could not verify that he was selling the drug. John Deits, an assistant U.S. attorney, said Berkan was identified by a 19-year-old who told police he had been buying marijuana from a U.S. Postal Service worker. The teenager said he had been buying the drug from Berkan for at least two years.