How likely is it really that this guy planned everything out all alone in his apartment, and only the two other cast mates knew of his plan?
3 years is a long time in prison, and that's not even including the time he'll get if it's proven he faked the powder-laced death threat mail. Not sure how well a gay celebrity actor will do in Chicago prison, so one can easily believe he will take a plea deal if he has information on other people who were involved in this hoax.
If the other people involved in this hoax are high level enough, it wouldn't be surprised if they "suicide" this guy, especially since most people wouldn't be surprised to hear of him committing suicide after flushing his reputation & career down the toilet.