Interrogation

Interrogation was sometimes necessary on informants and fellow Assassins that didn't tell one everything about a certain objective. If this happened, one could use this violent skill.

Method
For Altaïr to use interrogation, he needed to know his target, which was usually a public speaker that praised his current assassination target. As the target started walking away from the crowd, the Assassin followed him, and after a few minutes, usually alone or out of sight from the guards, he started beating up his target. After a few punches, the target would go down, kneeling and giving Altaïr his information. Altaïr would then kill him and leave immediately.

Trivia

 * If an interrogation target is attacked while one or more thugs are near by, they will join in the fist fight against Altair.
 * If an interrogation target is assassinated in front of a guard, the guard will not react and behave as if he is just discovering the body.
 * When you see a public speaker not surrounded by guards, you can run up and use the hidden blade to kill him. Interestingly, the listeners will just calmly walk away afterwards as if nothing had happened.
 * Interrogation missions disappeared in Assassin's Creed II, but returned in Assassin's Creed: Brotherhood.
 * Altaïr killed his interrogation victims after extorting information from them. This was done with a hidden blade.