A northern Minnesota man has been charged with intentional murder after an autopsy found that his ex-girlfriend, Rose Downwind, died of strangulation — not falling down the stairs, as he had told police.

The charge against Marchello A. Cimmarusti, 40, was changed in Beltrami County District Court this week from second-degree murder without intent, to second-degree, intentional murder, which carries a penalty of up to 40 years in prison.

Downwind, a 31-year-old Redby woman and mother of five, went missing in October, prompting searches of the area and pleas for information. Her body was found in December in the forest northwest of Bemidji, burned and buried in a shallow grave.

Cimmarusti initially told police that he didn't know where Downwind was, but later acknowledged that the two had argued on Oct. 20 in the Bemidji home where they had once lived together. He told police that when Downwind tried to report him violating a no-contact order against him, he pulled the cellphone from her and pushed her with his shoulder.

She fell down the cement stairs, he told police in December, hitting her head on the wooden landing below. Cimmarusti then led law enforcement officers to Downwind's body.

But an autopsy performed by the Ramsey County medical examiners office on Dec. 11 found ligature wire around Downwind's neck, court documents show. A vertebra was also fractured. The death was a homicide, the examiner reported, "most likely" caused by strangulation.

"Cimmarusti never mentioned the ligature wire around the neck of Rose Downwind," the amended complaint says, "which, although charred still existed subsequent to Cimmarusti and his accomplices burning Downwind's body after her death and prior to burial."

Two of Cimmarusti's friends face aiding and abetting charges for allegedly helping bury Downwind's body.