A good article to read on this - a friend of his posts why he thinks it was actually a suicide:
Why I DON?T Think ?Gray State? Director David Crowley Was Assassinated
Ordinarily I'd agree with you; I love the ones where investigative reporters with Pulitzer prizes and novels write "I'm sorry, especially to my family" before they "kill themselves". Bullshit. People get killed all the time in the interest of national security. If they'll send a good, trained soldier, who works for them, to his death, why not some peasant scumbag? Anyone who thinks this doesn't occasionally happen is hopelessly naive.
The greater good is the greater good in their eyes. Socialism has killed over 50,000,000 people yet idiot kids still believe Bernie Sanders wants to help them.
But in this one case, the facts strongly point to suicide.