Dr. Kevin Hartkans had been with the Stargate Program for seven months, and his clean record showed nothing out of the ordinary until video surveillance footage showed him apparently installing a locator beacon on the stargate. Two days later, the gate was beamed out of the SGC by members of the Trust using Asgard beam technology. The following day Dr. Hartkans went missing, he failed to report for duty, and his apartment was cleaned out.
Cross Reference: Trust
Episode Reference: Endgame