PORT HURON TWP., Mich. -

Officials have identified a body found this month behind a Michigan thrift store as that of an 89-year-old woman from Oregon.

The St. Clair County, Mich., sheriff's department announced Thursday that Mary Gertrude Grenia of Salem was identified using X-ray comparison from medical records.

A 49-year-old woman from Salem, Ore., who is believed to have dumped the body remains in custody in Illinois after being found earlier in Belleville, Ill. Authorities say she's expected to be transported to Michigan to face charges in the case next week.

READ: Suspect arrested in connection with body found in St. Clair County

The body was found March 12. Authorities have said it was hidden more than a week under snow and blankets behind the Goodwill store in Port Huron Township, about 55 miles northeast of Detroit. The cause of death hasn't been released.