"Agent Cobra I'm writing you up for violating our mandate on collateral damage."
-Teresa Lipan's voiceover, given in the debriefing in Syphon Filter: The Omega Strain if the player kills a civilian
Civilians are innocent non-combatants and are featured to some extent in the Syphon Filter series. Terminating them would be considered a violation of the IPCA's strict policy of collateral damage; as such, they must either be silenced with non-lethal force or ignored altogether. Civilians serve some purpose in each mission: players must sometimes rescue them from enemies.
There are multiple ways of dealing with civilians: for one, the player has an arsenal of non-lethal weaponry, more so in The Omega Strain rather than in any other game. Acceptable equipment for civilian combat includes the various tasers; the Stun Jack baton; the air pistol, DormaGen gas grenades and riot shotgun. However, the player must be careful where they aim, for headshots can kill even with such weapons, and prolonged exposure to the electric volt delivered by tasers can prove lethal. In some cases, they can be killed by enemies, but the player must avoid using lethal force.
Syphon Filter: The Omega Strain
Civilians are firstly seen in SFOS. During Krivorozhstal Mill, CDP soldiers are seen shooting a couple of workers. The player also encounters a total of 7 innocent mill employees who are unarmed and must be escorted to safety. Attacking them, even with a non-lethal weapon, would be considered killing them.
Civilians are seen again in Arms Bazaar, in which al-Hassan and his murderous attack dog Khorsh Wallid Abdul both torture a false confession from an innocent villager in Sana's. The man is presumably killed as seen by the player when infiltrating Khorsh's headquarters.
Mujari encounters civilians in Ivankov's village, and watches Uri Gregorav interrogate one. Far from killing the Russian, he takes a picture of him and lets him escape, allowing Gabe to handle him. The innocents are rescued and escorted to safety. It is implied that at least one villager was killed and Mujari is tasked with acquiring a tissue sample from the body.
They appear in North Atlantic: Lorelei Salvage Rig, in which unarmed workers patrol the area; these innocents must be neutralised with non-lethal force.
Syphon Filter: Dark Mirror
Civilians are seen in KemSynth Petroleum, where Red Section killed most of the personnel present and even burnt one alive. Two of them, William Kreisler and Malcolm Freeman, committed suicide rather than surrender information about Dark Mirror. The NSA operative Jack Miller was also killed in action.
They appear again in Iquitos, Peru, where Gabe Logan finds a dead body in the jungle. He also discovers dead bodies of more NSA personnel; two of them being David Carter and Mark Aldred.
They would also be seen in the Konigsberg Casino, in which Gabe discovers the place is being used as a temporary storage area for dead prostitutes.
Finally, they were seen in the Zuspitze Tram Pass in Germany, when Red Section takes them hostage. Gabe frees them, as well as a group caught in a malfunctioning elevator.
Syphon Filter: Logan's Shadow
Civilians appear during the Spetsnaz incursion of Azerbaijan, when the Russians are seen conducting genocidal activities. Trinidad and Gabe both witness multitudes being slaughtered, with one victim being a heavily pregnant female.
An occasional civilian is also seen by Gabe, who discovers multiple NIOC couriers killed by al-Jamil and Russian forces.