Alan Mace
From Tardis Wiki, the free Doctor Who reference
Colonel Mace was a British officer with UNIT. He wanted to lead an attack against the Sontarans but the Doctor convinced him otherwise after the deaths of a squad of soldiers including Ross Jenkins. He tried to launch a nuclear attack against the Sontarans, but the Martha clone wiped out the launch codes.
Mace co-ordinated the UNIT counter offensive at the ATMOS factory. Mace orders the Valiant to be used to clear the ATMOS gas. He killed Commander Skorr with a pistol. (DW: The Sontaran Stratagem/ The Poison Sky)