Police say Demons, 19, killed pals Anthony Williams, 21, and Christopher Thomas Jr., 19, and then tried to stage the crime scene with a Jeep to make it look like they had been the victims of a drive-by shooting.
Several days after the killings, Demons' lawyer Bradford Cohen said of his client, "He's sad, he's upset, obviously".
Cortlen Henry, 20, was arrested in connection with the shooting deaths.
Mr Henry was reportedly arrested in Texas last month and extradited to Florida this week. He was taken into custody and brought back to Broward County to face premeditated murder charges.
YNW Melly, whose real name is Jamell Demons, has been arrested and charged with murder, according to the Miramar Police Department.
Authorities say Demons and Henry staged the crime scene to resemble a drive-by shooting after Demons allegedly shot and killed Williams and Thomas. They were apart of Melly's "Young New World" collective and went by the monikers YNW Sakchaser and YNW Juvy respectively. Adding, "A couple months ago I lost my two brothers by violence and now the system want to find justice".
"Those were his best friends", he said.
Demons has a criminal history that includes charges of possession of marijuana and a firearm by a convicted felon, according to The Fader.