Answer:
Inductive reasoning
Step-by-step explanation:
Inductive reasoning is based on making broad generalizations from specific observations. We draw conclusions from the data we have. This is the opposite of deductive reasoning, which starts with a general statement and aims to reach a specific conclusion.
Based on this, we can conclude that, if an investigator uses their knowledge, training, experience, and expertise to reach a conclusion, they are using inductive reasoning.