BBM -This case has a VERIFIED INSIDER telling us with facts his opinion. Doesn't necessarily mean it's the be-all end-all of the case, though. <modsnip>
Finding an email that says "I want to end my life" would be very clear, but many people are far more oblique in what write down or tell people. You can't look at just the scene, or just the interviews/documents --- they (the ME) have to take it in as a total picture, and there is seldom 100% certainty. A scene with no homicidal violence and one text message that says "I'm worthless" could be enough to be ruled a suicide.