CONCORD, N.H. — A man has pleaded guilty in New Hampshire to participating in a conspiracy to distribute large quantities of heroin that has resulted in prison sentences for least five others.

Court documents say 30-year-old Ross Gould, formerly of Winchester, New Hampshire, started distributing the drug throughout Keene back in 2011. The drug trafficking expanded from mid-2014 to 2015, with Gould obtaining about 2 kilograms of heroin every four or five weeks from a source in Lawrence, Massachusetts.

Three people identified as drug couriers have been sentenced to prison terms ranging from eight to 11 years. Two people in Lawrence were sentenced to a little less than five years each.

Gould, who pleaded guilty Thursday in federal court, is scheduled to be sentenced on Jan. 30, 2018.