Security forces have decoded the secret words being used by DAESH to instigate terror attacks as well as tactics for attention diversion.

Security sources say that the group employed a method of diversion by recruiting "dead" suicide bombers. Members of the group designated for suicide bombings are portrayed as already dead or "martyrs" in clashes, before going into hiding and showing up at the sites of attacks - to the surprise of intelligence officials. Potential suicide bombers included on a wanted list released by the Interior Ministry were dismissed by DAESH after their names were revealed. Thus, the alleged Sultanahmet bomber, Nabil Fadly, was among those DAESH members who were not under surveillance by officials, resulting in him being assigned to the historical Istanbul district to commit the act of terrorism.

Intelligence gained about DAESH tactics was revealed after the capture of senior militants in the capital city of Ankara last month, who were planning to kill New Year's revelers in plotted suicide bombings around the city. Would-be suicide bombers in Ankara were ordered "to stay indoors" by their superiors after authorities discovered a sleeper cell. "It is snowing in Ankara, roads are slippery, stay at home," a message to the militants read, sent by an "emir," or senior DAESH commander, using a disposable cellphone. Quickly thereafter, sleeper cells that were unbeknownst to each other left their current locations and disappeared.

One day before the Istanbul attack, another message was relayed to DAESH suspects in Ankara. "It is sunny, you can go out," it read, meaning it was a safe time to conduct the attacks without detection. Security officials in Istanbul were warned of the attack at Sultanahmet but not before it was too late.