Hennepin County officials are asking for the public’s help identifying dozens of people whose deaths have gone unsolved.

The cases are highlighted as part of National Missing Persons Day taking place on Feb. 3.

National Missing Persons Day recognizes the thousands of people reported missing or found unidentified across the United States each year. Officials say more than 150 cases in Hennepin County remain classified as unidentified, with some dating back decades.

The Hennepin County Medical Examiner’s Office is leading the effort to review those cases using updated investigative tools and forensic technology that were not available when many of the original death investigations were conducted. Officials say advances in genetic genealogy, improved communication platforms and expanded case databases are increasing the chances of identifying people who previously remained unknown.