(written from a Production point of view)
Jef Jon Ayres is an actor who played Crewman Haynem during the run of Star Trek: Enterprise. Ayres also served as Connor Trinneer's stand-in for seasons 3 and 4, replacing Mark Watson. His only on-screen credit and a line of dialogue was in "These Are the Voyages...", Enterprise's series finale, where he was credited as "Medical Technician". In addition, Ayres portrayed a Klingon in an episode of Enterprise.
His Klingon boots were previously worn by actors Michael Dorn and John Vickery and were sold off on the It's A Wrap! sale and auction on eBay.  His Starfleet jumpsuit was also worn by stuntman Keii Johnston and cameo role actor Robert Pickering and was among the items which were sold off on IAW.  Ayres was also part of a deleted scene in sickbay from the episode "Minefield" which was added in the special features of the ENT Season 2 DVD.
Ayres acted in the films The Majestic (2001, with David Ogden Stiers, Mario Roccuzzo, Frank Collison, Ken Magee, and Earl Boen), A Man Apart (2003, with Geno Silva, Jeff Kober, Marco Rodriguez, Jim Boeke, Charlie Curtis, and Thomas Kopache), Good Bad Karma (2006, written, produced, and directed by David Takemura), Razor Sharp (2006, with Chic Daniel), and Dream Slashers (2007).
He has also appeared in the television series The Jamie Foxx Show, Popular, and Passions, as well as in several stage plays.
Star Trek appearances
(This list is currently incomplete.)