Brooks, 18, was also found guilty of illegal possession of firearm and arson in the Home Circuit Court in downtown Kingston today.
His co-accused, Andre Hinds, was also found guilty.
The two were arrested and charged in connection with the home-invasion killing of Lorenzo Thomas in the St Andrew community of Cassava Piece on June 5, 2018.
Prosecutors led evidence that Brooks and Hinds were among five men who entered the house and shot Thomas before pushing his father into another room.
Thomas’ killers attempted to sever his head, but aborted that plan because the machete was too dull.
They then poured gasoline on the house and body before setting them on fire.
Prosecutors relied on the eyewitness testimony of Thomas’ father, who indicated that he knew his son’s killers from the community.
Brooks and Hinds have been remanded into custody and are to be sentenced on March 10.