Interrogation was used by Assassins as one of the methods of investigation, in order to fully extract information from an individual, in regards to a certain objective. Whilst not completely ethical to other conventional means, an Assassin could use this violent skill in necessary circumstances.
As the target had finished talking and began to walk away from the crowd they were communicating to, the Assassin would follow them to a secluded area.
Once out of sight from the guards, he would beat his target, and after a few punches, the target would drop to their knees and give Altaïr the knowledge he required. Afterwards, to prevent them from informing anyone of the event, Altaïr would fatally stab them with his Hidden Blade and leave their body on the ground.
Though it bordered more on torture, Nikolai had Dolinsky tied to a chair whilst he beat him across the face and threatened his family, finally ordering two other Assassins to slit his throat after he disclosed the information about the Staff of Eden and Tunguska.
If an interrogation target is attacked while one or more thugs are nearby, they will join in the fist fight against Altaïr.
If an interrogation target is assassinated in front of a guard, they would not react, and behave as if they had just discovered the body.
When a public speaker was not surrounded by guards, Altaïr could run up and use his Hidden Blade to kill them. Strangely enough, the listeners would calmly walk away afterwards, as if nothing had happened.