I know something about mental health and suicide. Anyone who wonders why someone would go to such lengths to mask a suicide, doesn't have that much familiarity with suicide.
It is actually reasonably common that someone commits suicide, but tries to disappear rather than be remembered for the act of the suicide.
Also the willingness to murder innocents in the process is not quite so rare as people are making it out to be. Ask any policeman about what they think really happened in many head-on collisions that are classified as accidents.
If that is what happened here ... big if .... the elaborate nature of the plan may be mindblowing, but the essence of what is going on isn't very mindblowing.