OSAN AIR BASE, South Korea -- An Air Force sergeant who pleaded guilty to stealing money from a safe was sentenced Tuesday to 90 days in jail and loss of rank, officials said.

Tech. Sgt. Eva Zimmerman was reduced in rank to airman first class following a court-martial before military judge Col. Mark Allred.

The money was in an envelope and contained between $4,000 and $6,000 that had been donated for a U.S. 7th Air Force (Air Forces Korea) banquet.

Zimmerman spent it for her "personal use," officials said.

Zimmerman, sergeant-in-charge of executive support services with 7th Air Force’s 607th Support Group, had been charged with larceny that occurred sometime between Sept. 15 and Nov. 20, officials said.

"Officials went to look for the money and to account for it and found out it was missing, and that is when the investigation started" that led to Zimmerman’s court-martial, said 1st Lt. Naomi C. Evangelista, an Osan spokeswoman.

Zimmerman had opted to be tried by judge alone rather than a jury.

She was to be taken Tuesday to the 8th U.S. Army Confinement Facility at Camp Humphreys to begin serving her sentence.