Trump called the situation an "embarrassment to our nation" in an early-morning tweet on Thursday.
The brothers have not spoken about the case since police said they confessed to being paid to stage the attack.
The 61 pages were released in response to Freedom of Information Act requests from the media and do not appear to offer many major revelations about what investigators allege was Smollett's hoax. The actor said two men attacked him at 2 p.m. when he was walking home from a sandwich shop, poured what he believed to be bleach on him, and placed a rope around his neck.
On Thursday morning, President Donald Trump announced that the Department of Justice (DOJ) and the FBI would investigate the hate hoax perpetrated by Empire star Jussie Smollett.
Police said investigators believe Smollett, who is black and gay, hired two brothers to stage the early-morning January 29 attack in downtown Chicago, and that Smollett hoped it would gain attention and help advance his career.
Prosecutors dropped all charges against Smollett in a stunning move on Tuesday.
"Mr. Smollett, like every citizen, is innocent until proven guilty in a court of law". The FBI, which is investigating that letter, has declined to comment.
In a series of interviews on Wednesday, she said that what had been agreed between his team and hers was what is known as "alternative prosecution" whereby a defendant agrees to a certain set of term and has the case dropped in exchange.
Cook County first assistant state attorney Joe Magats told ABC Chicago station WLS Tuesday that the charges against Smollett were dropped in favor of an "alternate resolution" in order to focus resources on violent crimes, since it was a low-level felony, he had no criminal history. Smollett was allowed to walk free after forfeiting his $10,000 bail and performing 16 hours of community service, to which Foxx said, "I believe this is a just outcome based on the circumstances".
State's Attorney Kim Foxx insists Smollett was treated the same as others charged with Class 4 felonies, who rarely go to prison. She also said she "recused" herself from the case, citing those communications, but did not withdraw the whole office and seek a special prosecutor.
Chicago Mayor Rahm Emanuel wants Smollett to pay, literally.