A Bemidji man has pleaded guilty to killing his ex-girlfriend last fall. 40-year-old Marchello Cimmarusti pled guilty to second degree murder in the death of Rose Downwind of Redby. The 31-year-olds body was found in a shallow grave northwest of Bemidji in December. Cimmarusti told police he accidentally killed Downwind when she fell down stairs during an argument. But an autopsy found she had been strangled. Downwind was the granddaughter of American Indian Movement co-founder Dennis Banks.