

To clarify, murder can be prosecuted at either a state or federal level.
First, from a state perspective, we are definitely dealing with a first degree murder charge. That would meet the requirements of willfull, deliberate, and premeditated murder. They will also likely be aiming for a finding of express malice, meaning they want to prove he had the frame of mind that he wanted to cause the harm as the primary end point, not just as a secondary part of doing something else like robbery or rape.
With regards to a federal charge, I will include the appropriate code.
18 U.S. Code § 1111 – Murder
(a)Murder is the unlawful killing of a human being with malice aforethought. Every murder perpetrated by poison, lying in wait, or any other kind of willful, deliberate, malicious, and premeditated killing; or committed in the perpetration of, or attempt to perpetrate, any arson, escape, murder, kidnapping, treason, espionage, sabotage, aggravated sexual abuse or sexual abuse, child abuse, burglary, or robbery; or perpetrated as part of a pattern or practice of assault or torture against a child or children; or perpetrated from a premeditated design unlawfully and maliciously to effect the death of any human being other than him who is killed, is murder in the first degree.
Any other murder is murder in the second degree.>
So from a federal perspective the same basic stuff applies. Did he do the act? Was it committed with express intent? If so, first degree. If not, second degree.
Under normal circumstances I do it believe this would merit a federal case, rather it should be a state case. Normally it is federal if it is an interstate hitman, a bank robbery, something that happened on a ship (because it is not in the land of a state), if the murder was drug related, if it was intended to influence a federal case outcome, if it was in the process of some fairly nasty child abuse cases, or if the person targeted was a federal officer or judge. As far as I can tell none of the above hold.
So one of the most important things here is that in both cases the prosecution has to show, with untainted and admissible evidence, the express intention to kill the CEO. This means if that evidence, his supposed manifesto, is not admissible due to failure to obtain a warrant, appropriate procedure for the execution of the search, and maintaining the chain of custody of the evidence, then it may not be admissible. He could completely skate on the first degree charges based purely on their incompetence at doing the search legally.
A second question is whether his initial arrest was valid. If they failed to maintain correct process in the actual arrest, failed to read his rights etc, failed to give him access to a lawyer on his request, that could taint the whole arrest.
The lawyer has already raised numerous issues with his arrest and the conduct after it. The leaking of the “manifesto” may have tainted the jury pool. The jokeresque pictures of Luigi in chains with 30 cops behind him may also have tainted the pool. The sheer amount of coverage may preclude an unbiased jury pool. Not to mention that the odds of finding 12 jurors plus however many alternates who have not been impacted by the USAs dismal healthcare system are pretty freaking slim. It could be a mistrial just from that.
This is a major clusterfuck from start to finish for the police and prosecutors. Nobody did this right, they took shortcuts and got carried away, and the media attention was so intense it could all just fall apart.
Hopefully they actually respect his legal rights to some degree and have borked the process enough for him to walk free. It may end up in a total dismissal of all the serious charges with only the possession of a fake ID and so on standing, though given how poorly they handled the evidence maybe not even that.