Sanchez

Lieutenant General Sanchez was a US Army general and a high-ranking UNIT officer.

Biography
Sanchez was in command of at least one UNIT base, and possibly UNIT's American branch.

At one point, Sanchez met Sarah Jane Smith. A photograph of this meeting was located in the Black Archive. (TV: The Day of the Doctor)

When the Daleks invaded the Earth in 2009. Martha Jones worked under him at that time as the Medical Director of Project Indigo, an experimental teleportation system which used Sontaran technology. Sanchez reported that Geneva had declared an Ultimate Code Red when the Dalek message of Exterminate! was conveyed to the human race.

When the Daleks invaded UNIT's base in New York City, Sanchez ordered Martha to escape by means of the Project Indigo prototype. He also gave her and authorised her to use the Osterhagen Key. Sanchez and another soldier attempted to fight the Daleks as Martha teleported to safety. (TV: The Stolen Earth)

Within UNIT hierarchy
As a General, Sanchez ranked above Colonel Mace, of the British branch of UNIT. He held the power to authorise use of the Osterhagen Key. He still took orders from Geneva.

Behind the scenes

 * His right-sleeve shoulder patch indicates that he previously served in a combat theatre with the . His left shoulder bears a Ranger tab, indicating he successfully completed Ranger School. A Master Parachutist Badge can clearly be seen on the left breast pocket of his uniform coat, underneath his ribbons, along with a Pathfinder Badge, in the scene where he approaches Martha saying that Project Indigo is being activated and in scenes thereafter.
 * Sanchez uses the term "quick march" when speaking to Martha. Either he is using the British command in deference to Martha's nationality (the equivalent American term is "double time") or this is another example of British word usage seeping into the dialogue of American characters, such as those in Peri Brown and Canton Everett Delaware III's dialogue. Sanchez also uses a classic British stance when firing his sidearm, rather than the two handed weaver stance preferred by the US Military (or the one-handed casual stance used in American media). Also despite being an American Officer he is equipped with a revolver rather than a M1911 or Beretta M9 which are the standard service pistols of the US Armed Forces.