Which of the following is NOT a step in Eoghan Casey's model of investigation?

In Eoghan Casey's model of investigation, the steps involved primarily focus on handling and analyzing digital evidence, which typically includes stages such as examination, identification/assessment, and preservation. Interrogation, while a crucial part of many investigative processes—especially those involving human subjects—is not a formal component of this specific model.

The examination stage revolves around analyzing the digital evidence for any pertinent information, while identification/assessment is about determining what evidence is relevant to the investigation and assessing its condition and significance. Preservation refers to the necessary steps taken to protect and maintain the integrity of the evidence for both future analysis and legal considerations.

Since interrogation does not pertain directly to the technical aspects of data and digital evidence analysis, it is not included in Casey's model and therefore is the correct answer for what is not a step in his proposed framework.