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Press Release

Nurse Sentenced to Federal Prison for Stealing Pain Medication from Patients and Fined $20,000

For Immediate Release
U.S. Attorney's Office, Northern District of Iowa

A Carroll County registered nurse who stole controlled substances from patients and falsified medical records at a life care center where she was employed was sentenced today to 7 months in federal prison and ordered to pay a $20,000 fine.

Cassandra Lynne Vonnahme, age 32, from Arcadia, Iowa, pled guilty to one count of acquiring a controlled substance by means of misrepresentation, fraud, deception, and subterfuge, and one count of false statements relating to health care matters on November 30, 2023. 

Vonnahme admitted that between November 2020 and December 2020, she diverted controlled substances and falsified related medical records.  The controlled substances Vonnahme stole and the records she falsified pertained to actual patients.  Evidence at sentencing also revealed that Vonnahme burglarized 5-6 homes after losing her job as a nurse for stealing patient’s medication.  Vonnahme was later convicted of impersonating a public official after another burglary in Carroll County in 2021, where she pretended to be a county assessor in order to gain entry into a stranger’s home and then stole controlled substances. 

Vonnahme was sentenced in Sioux City by United States District Court Judge Leonard T. Strand to 7 months’ imprisonment and fined $20,000.  She must also serve a 2-year term of supervised release after the prison term.  There is no parole in the federal system.  Vonnahme was released on the bond previously set and is to surrender to the Bureau of Prisons on a date yet to be set.

The case is being investigated by the Iowa Department of Inspections & Appeals, Medicaid Fraud Control Unit and is being prosecuted by Assistant United States Attorney Ron Timmons. 

Court file information at

The case file number is 23-4019.

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Updated May 17, 2024

Prescription Drugs