Alex Hopkins was the leader of Torchwood Three in 1999. He murdered the entire team except the immortal Jack Harkness.
He was given an offer to spy on Torchwood for the Committee, but he declined. (AUDIO: The Torchwood Archive)
On New Year's Eve 1999, Alex gathered the Torchwood Three team, including Karen Baldwin and James Unsworth, in the Hub, except for Jack, and killed them. Jack arrived to find the carnage. Hopkins then shot himself. With everyone else now dead, Jack took over as leader of Torchwood Three. Hopkins had killed himself and the others as the Last of Erebus showed him the team unprepared for upcoming dangers in the 21st century. (AUDIO: The Torchwood Archive) He spoke of a storm coming which humanity could not face. (TV: Fragments). He told Yvonne Hartman about this on the same night on the phone, as he shot the team. (AUDIO: One Rule)
Under Torchwood policy, his personal possessions would have been stored in a warehouse per Torchwood policy. (TV: They Keep Killing Suzie)