CARLTON — A Duluth man has been sentenced to 30 years in prison after pleading guilty to killing a woman after arguing about drugs.

Twenty-three-year-old Michael Siewert admitted strangling Christyna Watson and hitting her in the head with a hammer. Her body was found outside a home on the Fond du Lac Reservation last October after she had been missing for about a month.

Siewert is accused of taking Watson’s car and trading it for 2 ounces of methamphetamine in the Twin Cities.

Two other adults were charged with helping Siewert cover up the crime.

Siewert also pleaded guilty in a separate case for an assault with a weapon and was sentenced to 4 1/2 years in prison to be served at the same time as the murder sentence.