(CNN) -- A 59-year-old Michigan woman has been charged in connection with the death and dismemberment of the woman's 32-year-old son, a sheriff said Monday.
Donna Scrivo was arraigned in St. Clair Shores, Michigan, on charges of disinterment and mutilation of a body, St. Clair County Sheriff Tim Donnellon said at a news conference.
Body parts identified as those of Ramsay Scrivo, the suspect's son, were found in garbage bags dumped along Michigan roads, according to law enforcement officials.
Officials at the press conference said they expect more charges to follow. An autopsy is not complete and a cause of death has not yet been determined, Detective Sergeant Jay Cohoe said at the news conference.
According to court documents, Donna Scrivo filed a petition seeking hospitalization for mental illness of her son in May and was granted guardianship.
The petition was filed shortly after Ramsay Scrivo's father's death, Cohoe said.
"From what I understand, it (the father's death) did have a negative impact on the family," Cohoe said.
Officials stated that there was no history of assault allegations between Donna Scrivo and her son but police had been to the home on disorderly complaints.
The body parts were found Thursday and Friday at five different locations in St. Clair County, a few miles from the Canadian border.
A witness told police she saw a middle-aged woman in a light-colored SUV dumping what she initially thought was garbage in the area.
Security camera footage from the area confirmed the witness' account.
"A suspect vehicle was identified and images broadcast of a person of interest," the St. Clair Shores police and the St. Clair County Sheriff's Office said in a joint news release Saturday.
Ramsay Scrivo had been missing since January 26. His remains were identified through fingerprints.
"He would sit outside, very friendly," a neighbor told CNN affiliate WDIV. "Well-respected, everyone talked to him. He would say hi to everybody."
Donna Scrivo was being held with bail set at $100,000, and with a preliminary hearing set for February 14, according to officials at the news conference.
She had not obtained an attorney as of Monday afternoon, officials said.
CNN's Joe Sutton and Rick Martin contributed to this report.