Gordon Thorson was an agent with the Federal Bureau of Investigation. He and Rachel Walling were partners for a time. They fell in love, married, and divorced 15 months later. Walling was his second marriage and divorce. He had a caustic personality but was also an astute agent.
In early 1995, when he was part of the Critical Incident Response Team, he was assigned to the Poet task force. He worked with both Walling and Jack McEvoy on the task force, resulting in much interpersonal friction. When Thorson helped determine that suspect William Gladden would be visiting a camera store to buy a new camera, the FBI set up a stakeout at that location. Thorson was stationed inside the store posing as a store employee. Gladden entered the store disguised as a woman. Thorson pulled his gun to make the arrest, but Gladden was slightly faster with a knife. Thorson was stabbed in the neck and died quickly.