Two Mississippi sisters pleaded guilty Monday to distributing synthetic marijuana and laundering millions of dollars from the sales, federal officials said.

A U.S. Department of Justice news release said Kimberly Drumm, 51, and Bonnie Turner, 49, of Olive Branch, Mississippi, pleaded guilty on Monday in federal court in Alexandria, Virginia.

Court documents said the two women and a co-defendant led a southern California-based operation from which buyers could order synthetic marijuana, sometimes referred to as “spice.” The operation ran from 2017 through November 2019, prosecutors said.

The “spice” contained chemicals listed as controlled substances and was sold in packages labeled “Not For Human Consumption” in an attempt to avoid scrutiny, prosecutors said. The products were intended for use to induce a high, the news release said. The “spice” connected to the scheme led to a fatal overdose by a New Hampshire resident, according to prosecutors.

Drumm, Turner, and the co-defendant concealed proceeds from their operation by moving profits through a network of shell corporations, prosecutors said.

The sisters face a maximum of 20 years in prison when they are sentenced on Feb. 17, 2021, the department said.