It's depressing to think that I'd have to have perfect mental health and the appearance of perfect mental health to arise suspicion otherwise my suicide would be written off. This is, of course, literally impossible.
Even assuming I did, almost anything bad that happened to me prior to the murder (losing a loved one, going to prison, being unable to go home, being arrested, stories of how you mistreated your cat) could be used to push for the idea of it being a suicide on mental health grounds. If Snowden were offed tomorrow, for example, there would be a veritable chorus of believed people declaring him mentally unwell whether or not there was any clinical evidence for it.
Any additional "craziness" from my past (& most people have some) adds fuel to the fire. Any evidence that you considered suicide in the past then you're practically a write off.
The fact that even foreshadowing it by saying "I would never commit suicide" would be used as evidence that I'm crazy (because "normal" people don't do that) is truly depressing. I thought this would work but it appears it's too easily dismissed as somethihg only a kook would do because Occam's razor.
Assuming the other evidence can be dealt with quietly (videotape, autopsy, etc), state sanctioned murder of dissidents and whistleblowers this way seems fairly easy. Moreover, if you're a whistleblower or dissident with real mental health issues or god forbid have attempted it before a staged suicide is a very logical way of dealing with you. The public is primed to write it off without a second thought.