Ensign Tom P. Mahoney was a Starfleet officer during the Dominion War.
In 2374, a file from the starship USS Akagi reported Mahoney missing in action. A file from the USS Zapata reported him killed in action. (DS9: "In the Pale Moonlight")
This character was only mentioned in writing.
Mahoney's name appeared on the casualty list
display seen on a computer
readout in that episode. It is unclear which of the above was his home station, if any.