When a Jedi Knight began their independent studies separate from their former Jedi Master, they had the option of choosing from three classes of Jedi: the Guardian, Consular, and Sentinel. A sniper of the Jedi Temple Security Force was a Guardian who pursued the specialization of Peacekeeper based on Coruscant.
Stationed on the parapets around the Temple Precinct, Temple snipers excelled at using their lightsabers as ranged weapons and used the Force to enhance their vision as well as to help guide their long-range shots. Perfecting their telekinetic lightsaber forms, snipers were also highly acrobatic, capable of jumping, flipping, and running without the direct aid of the Force to propel themselves.
The rank of Temple snipers dates as far back as the Ruusan Reformation and the reorganization of the Jedi Order by Grand Master Fae Coven. Codifying the ranks and duties of the Jedi in her handbook called The Jedi Path: A Manual for Students of the Force, the term was used up until the dissolution of the Order in 19 BBY. When the Supreme Chancellor of the Galactic Republic was revealed to be a Sith Lord, he quickly ordered the Grand Army of the Republic to turn on the Jedi before they could remove the Sith from office. Darth Vader, the Sith Lord Darth Sidious' new apprentice led the 501st Legion against the Temple conducting Operation: Knightfall as part of Contingency Order 66. The snipers of the Temple defended it valiantly against the Sith and his army but were vastly outnumbered. By the end of the night, not a single sniper had survived the order. There were a total of 200 Jedi snipers on the day the Jedi Order fell.