Matthews was a member of the military and the Atlantis expedition. In 2007, he was working with two scientists on the East Pier of Atlantis when it was stranded in space after the Asurans' attack, trying to repair damage to the city. When the shield started to collapse, they raced to a nearby transporter, but did not make it in time and were killed when the area they were in underwent decompression. (SGA: "Adrift")