Under US law, can Justice department stage fake assassination for WPP?

[moderate libertarian]

Recently saw a 1986 made movie called FX. Plot is sensational, US Justice department recruits a talented Special Effects expert from movie industry to clone a mob figure and then direct his staged assassination in public as part of witness protection program. After mission is carried out, the life of the man who did this operation is in danger as his recruiters want to eliminate him so there are no "loose ends". This was the movie:

http://www.imdb.com/title/tt0089118/

While watching the movie, I wondered if this is just stuff for movies or can happen in real life too. Can any US agencies including CIA legally carry out staged fake killings for WPP or other reason?

I didn't believe some claims about OBL killing being staged after photos shown to some US Senators later turned up being special effects fakes and 30 members of elite navy seals unit involved in that operation were killed shortly afterwards in a helicopter crash in Afghanistan. But there is remarkable similarities in movie plot and what skeptics of government report of OBL killing claimed.

[Philhelm]

Some here believe that 9-11 was an inside job, whereas I believe it was blowback. I'm not one to call others conspiracy theorists, as a conspiracy is simply two or more people planning and making steps toward committing a crime. That happens every day. Who knows what the truth about 9-11 or Osama bin Laden is? But does it really matter? We all know that our government is corrupt to the core. It has committed thousands, if not millions, of crimes against the citizens of the U.S.

[moderate libertarian]

This question was primarily if real life imitation of plot shown in the special effects movie would be legal under US laws covering overt/covert agencies?
I think answer to question like this does matter.

Some people believe aliens have visited is. So there are all sorts of conspiracy theories. I also believe 9/11 was a blowback, some foreign spy agencies may have had advanced knowledge of it and did not share with US.

Since you brought it up, so far I have believed in only one conspiracy theory that the government claims suggesting Iraqi WMD threat were fake. That turned out to be "fact" few years later.

I would say this though that after watching this movie, I'm not as sure about government claims about 2010 OBL killing as I was before watching the movie.