Ensign John A. Fredrickson was a Starfleet officer during the Dominion War.
In 2374, files from USS Cochrane, Starbase 129 and Starbase 153 all reported Fredrickson killed in action. (DS9: "In the Pale Moonlight")
This character was only mentioned in writing.
Fredrickson's name appeared on the casualty list
display seen on a computer readout in that episode. It is unclear which was his home station, if any.