Cerberus Automated Turret Schematics is a Mass Effect 3 Citadel mission that can be completed while playing the Tuchanka: Turian Bomb side-mission.
When to start
After Priority: Surkesk
“A C-Sec officer needs a way to detect or deactivate Cerberus turrets left behind on the Citadel.
Find Cerberus automated turret schematics and bring them to him in the Presidium Commons.”
Citadel Defense Force War Asset
Once you get the schematic during your visit on Tuchanka, look for the C-Sec officer in Presidium Commons, but make sure you do that after the first mission of the second act, otherwise you wont be able to see him.
He is standing on top of the stairs, looking at the gardens.
Next Citadel mission: Barla Von.