A grand jury indicted Dedrick Williams, 22, Michael Boatwright, 22, Trayvon Newsome, 20, and Robert Allen, 22 on first-degree murder and armed robbery charges, court records showed.
XXXTentacion, whose real name was Jahseh Onfroy, was shot dead as he was leaving a motorcycle dealership in Deerfield Beach last month.
According to a warrant filed in Boatwright's case, the car driven by XXXTentacion was blocked by a dark-coloured SUV as it was exiting the Riva Motor Sports shop.
Two masked men got out of the SUV with a gun intending to rob XXXTentacion, who had a Louis Vuitton bag containing $50,000 (£38,000) in cash, police said.
A struggled ensued and the 20-year-old rapper was shot multiple times by one or more gunman, who took the bag and fled, authorities said. The indictment names Boatwright as the person who fatally shot XXXTentacion.
Williams was arrested two days after the shooting, and Boatwright was arrested earlier this month on an unrelated drug charge. Authorities continue to search for Allen and Newsome.
Williams was seen in the store on surveillance cameras while XXXTentacion was shopping, court records show. A store clerk said Williams purchased a black neoprene mask and that he recognised Williams as a repeat customer, according to the warrant.
Williams later told police he was with others at the motorcycle shop but did not know in advance they intended to rob the rapper, according to records. Authorities say Williams drove the SUV.
"Williams stated that he wanted to tell the truth... Williams stated he was fearful of being labelled a snitch when he went to prison," the warrant says.
Police said Williams' girlfriend told them he had said he was involved but it was Boatwright and Newsome who carried out the robbery and killing. Police also found data on Boatwright's phone indicating it was near the motorcycle shop at the time of the killing, according to authorities.
Other evidence includes mobile phone video and photos with three of the suspects holding large amounts of money, police said.
XXXTentacion, who sported dreadlocks and facial tattoos, was a platinum-selling rising star who tackled issues including prejudice and depression in his songs. He also drew criticism over bad behaviour and multiple arrests, including charges that he beat and abused his girlfriend.
Additional reporting by PA.