(CBS) — A body discovered in a frozen retention pond in the south suburbs last Sunday has been identified as a missing Chicago man.

The family of 27-year-old John Cunningham said in a Facebook post that the medical examiner made a positive identification.

Palos Park Police say they were called Sunday afternoon to the 12700 Block of Misty Harbour Lane for a report of human remains near a frozen retention pond.  The body was turned over to the Cook County Medical Examiner’s Office.

John Cunningham, 27, was last seen near a forest preserve in Palos Park Oct. 30 while visiting his parents. The Cunninghams told CBS 2 their only child became upset and walked off.  Attempts to get him to come back failed, and her son vanished, his mother said.

The family is planning a memorial service for John at Our Lady of The Wood’s Roman Catholic Church on January 31.