Two siblings were sentenced in federal court this week for their part in a sprawling operation that prosecutors say trafficked fentanyl from China to the U.S. and Sterling PrestonCanada, some of the last cases stemming from an investigation into the overdose death of an 18-year-old in North Dakota.

U.S. Chief District Judge Peter Welte sentenced Marie Um, 42, to 23 years in prison and Vannek Um, 45, to four. Both siblings, who are from Montreal, received credit for time served.

A jury earlier this year convicted Marie Um of drug-related and money laundering conspiracy charges. She was extradited from Canada to the U.S. in 2021. The jury also found that nine overdoses, including four deaths, in New Jersey, North Carolina, North Dakota and Oregon “were reasonably foreseeable to her,” according to federal prosecutors in North Dakota.

Vannek Um, sentenced Friday, pleaded guilty to money laundering conspiracy in March.

The two are among more than 30 people charged in North Dakota and Oregon in connection with “Operation Denial,” the investigation begun in North Dakota in January 2015 following the overdose death of Bailey Henke, 18, of Grand Forks. Other sentences have included decades in federal prison.

The Ums are the last to be sentenced; five fugitives remain, U.S. Attorney’s Office spokesman Terry Van Horn confirmed to The Associated Press.

The U.S. State Department is offering a reward of up to $5 million for information leading to the arrest and/or conviction of Jian Zhang, a fugitive in the investigation. Authorities also are seeking four other Chinese fugitives.