ST. CLAIR SHORES, Mich. -

A 60-year-old St. Clair Shores woman now faces first degree premeditated murder charges in connection to her son's death and dismemberment.

Donna Scrivo originally was charged with dismemberment and removal of a body after her 32-year-old son Ramsay Scrivo's remains were found in early February in five different bags scattered along roads in China Township.

The Macomb County medical examiner has ruled Ramsay died from asphyxiation.

Police say an investigation led to surveillance videos of Donna Scrivo purchasing the Skilsaw used to dismember her son's body. The saw was found in one of the bags of body parts. Investigators also found DNA evidence in the trunk of Donna Scrivo's vehicle.

Scrivo reported Ramsay missing on Jan. 27 and called daily to check with police on the status of the case.

She is being held at the Macomb County Jail without bond. She is expected to undergo psychological evaluation to determine if she is competent to stand trial.

There is no date scheduled for Scrivo to appear in court to face the charges.