Smollett originally claimed he was attacked on Jan. 29 in Chicago around 2 a.m. in freezing temperatures by two white men who shouted slurs at him and said "this is MAGA country," an apparent reference to Trump’s slogan "Make American Great Again."
"They punched him a little but as far as we can tell, the scratches and bruises on his face were likely self-inflicted," Chicago Police Superintendent Eddie Johnson said at a press briefing on Feb. 21.
Smollett surrendered to police at 5 a.m. on Thursday, officials said.
In the press conference, police officials said they scoured footage from a number of surveillance cameras, both public and private, in the Streeterstown neighborhood to solve the case.
That included tracking the Osundairos to the airport and discovering that they flew to Nigeria just hours after allegedly carrying out the attack at the behest of Smollett.
The brothers were detained when they flew back into the United States in mid-February.
"While we were waiting for them to return we executed over 50 search warrants and subpoenas ... phone records, social media records, and records on individuals to help us illuminate the likely facts that occurred in this event," Chicago Police Commander Edward Wodnicki said at the briefing.
After speaking to the brothers, police worked on verifying the information that was conveyed until Smollett was officially classified as a suspect.
The letter also contained a white powder and prompted a police response on Jan. 22, the day it was received on the set. The white substance was later determined to be aspirin.
The brothers reportedly told police that Smollett was upset that the letter didn’t get a “bigger reaction,” prompting him to orchestrate the fake hate crime attack in Chicago, which has steadily turned into an investigation of Smollett as evidence mounts of a hoax being perpetrated.