"I think what's always been interesting to me than the science and the criminality with this job is what happens to your persona, your disposition, after day in and day out dealing with life and death"

George Eads is describing the psychological effects of his job as a criminal activity scene private investigator. He is recommending that the task can take a toll on one's mental health, as it includes handling life and death every day. This can be a tough and emotionally draining experience, and it can have a long lasting influence on one's character and outlook on life. He is implying that the task can be more than just a clinical and criminal pursuit, but also an individual journey. He is recommending that the job can be a transformative experience, which it can shape one's identity and outlook on life. He is stressing the significance of looking after one's psychological health when handling such a tough job.