Dear Mr. Mohnac,
Thank you for posting your request on History Hub!
We searched the National Archives Access to Archival Databases (AAD) and located the series World War II Prisoners of War Data File, 12/7/1941-11/19/1946 in the Records of the Office of the Provost Marshal General (Record Group 389) that includes one data file for a Capt. Alex M. Mohnac. These records can be used to confirm prisoner of war status and to provide other information like serial number, unit number, and POW camp name. We also searched the series World War II Prisoners of the Japanese File, ca. 1941 - ca. 1945 in the Records of the American Defenders of Bataan and Corregidor (Collection ADBC) that includes another data file for Capt. Alex M. Mohnac. For information about these records, please see their series descriptions here and here in the National Archives Catalog. Please contact the National Archives at College Park - Electronic Records (RDE) at firstname.lastname@example.org with any questions you might have about them.
Next, we searched the National Archives Catalog and located the series Diaries and Historical Narratives, 1940-1945 and the series Records Relating to Claims and Indexes, 1944-1945 in the Records of the Adjutant General’s Office, 1917 - 1985 (Record Group 407) that were created by the Recovered Personnel Division and might contain some information related to your search. Some of these records have been digitized and may be viewed online via the Catalog. Please contact the National Archives at College Park - Textual Reference (RDT2) at email@example.com for assistance with the non-digitized records. Other series were created by the Recovered Personnel Division and are described in the Catalog as well.
In addition, we located the series Far East Name Index to the Series "Case Files, 1944-1949" in the Records of the Office of the Judge Advocate General (Army) (Record Group 153) that includes 6 index cards related to the name Alex M. Mohnac (see images 333 - 336 & 343 - 344). The index cards have been digitized, and you may view them online using the Catalog. The case numbers 35-9, 35-1664, 35-1665, and 35-1666 listed on the cards relate to records in the series Case Files, 1944-1949. The file for case 35-9 is located in box 616 and the files for cases 35-1664, 35-1665, and 35-1666 are located in box 816 of the series. These records have not been digitized. Please contact RDT2 for access to and information about these records.
Finally, if you have not done so already, we suggest that you request a copy of your father’s Official Military Personnel File (OMPF). OMPFs and individual medical reports for those who served in the U.S. Army during WWII are in the custody of NARA's National Personnel Records Center (NPRC) in St. Louis. In many cases where personnel records were destroyed in the 1973 fire, proof of service can be provided from other records such as morning reports, payrolls, and military orders, and a certificate of military service will be issued. Please complete a GSA Standard Form 180 and mail it to NARA's National Personnel Records Center, (Military Personnel Records), 1 Archives Drive, St. Louis, MO 63138-1002. Veterans and their next of kin also may use eVetRecs to request records. See eVetRecs Help for instructions. For more information see Official Military Personnel Files (OMPF), Archival Records Requests.
Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDE and RDT2. Also, the NPRC is closed except for emergencies. Currently, NPRC will continue servicing requests ONLY associated with medical treatments, burials, and homeless veterans seeking admittance to a homeless shelter. If your request is urgent, please see Emergency Requests and Deadlines. Please refrain from submitting non-emergency requests such as replacement medals, administrative corrections, or records research until NPRC returns to pre-COVID staffing levels. Please check archives.gov/veterans for updates to the NPRC operating hours and status. We apologize for any inconvenience.
We hope this is helpful. Best of luck with your family research!