Sanchez

"Geneva are declaring Ultimate Code Red! Ladies and Gentlemen, we are at war."

- Sanchez

Lieutenant-General Sanchez was a high-ranking UNIT officer.

Biography
Sanchez was in command of UNIT when the Daleks invaded the Earth in 2009. He appointed Martha Jones, the Medical Director of Project Indigo, a teleportation system developed which used Sontaran technology. Sanchez and the United Nations 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 and another soldier attempted to fight the Daleks as Sanchez ordered Martha to escape by means of the Project Indigo prototype. She took the Osterhagen Key with her. Sanchez's was exterminated by Daleks after Martha teleported to safefty. (DW: The Stolen Earth)

Within UNIT hierarchy
Sanchez ranked above Colonel Mace. In 2009, Sanchez was the overall Head of UNIT, whilst Mace was in charge of the UK division. Sanchez answered to the Commander-General of the United Nations who later heard surrendering to the Daleks after the death of Sanchez and the fall of UNIT. (source?)

Behind the Scenes
Sanchez carried a revolver with a ivory style grip much like General George Patton in World War 2. Such a weapon is currently not accepted for use in the United States Armed Forces, and it is against regulations to use one as a personal sidearm. However, Sanchez is on detached duty with UNIT and as the head of UNIT could have most likely any sidearm he desired)

His shoulder patches indicates that he is from the 82nd Airborne Division, as well as a U.S. Army Ranger. However, his uniform does not include a Parachutist's Badge, (indicating that he has complete Jump School training), which is a requirement for members of both units.