A South Dakota jury convicted a man of killing his girlfriend and dumping her dismembered body in a river in Michigan’s Upper Peninsula last year.

Jurors in Yankton on Tuesday found 45-year-old Stephen R. Falkenberg guilty of first-degree manslaughter and second-degree murder in the March 1 death of 46-year-old Tamara LaFramboise.

Falkenberg is scheduled to be sentenced March 2. He faces life and prison and up to $100,000 in fines.

Prosecutors said in court documents that Falkenberg told his sister he argued with LaFramboise, pushed her and she hit her head and died.