Chicago, IL – Cook County investigators are renewing attention today on a long-standing missing persons case involving Nancy Marie O’Sullivan, who disappeared from South Holland on March 7, 1974. O’Sullivan was 15 at the time and is now listed as age 66 in the updated bulletin shared by the Cook County Sheriff’s Office.
According to the Cook County Sheriff’s Office, O’Sullivan was last seen in the South Holland area and is believed to have been the victim of foul play. The case is part of the county’s expanded Missing Persons Project, which is highlighting unresolved disappearances in hopes of generating new leads from the public.
Officials released an updated missing-persons bulletin that includes O’Sullivan’s characteristics at the time she disappeared, along with her current estimated profile. The Sheriff’s Office stated that investigators remain committed to re-examining evidence and gathering new information that could help determine what happened more than five decades ago.
The Sheriff’s Office is urging anyone who lived in South Holland, Cook County, or surrounding communities in 1974 — or anyone who may have heard details about the case in later years — to come forward. Detectives emphasize that even small or previously overlooked information could be valuable as they continue to review the circumstances surrounding her disappearance.
Residents can contact the Cook County Sheriff’s Special Victims Unit at 773-674-9490 or email ccsomissingpersons@ccsheriff.org. Additional information about the county’s missing persons initiative can be found at cookcountysheriffil.gov/person.
This article was produced by a journalist and may include AI-assisted input. All content is reviewed for accuracy and fairness.
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