Arellano's body was found early last month. He had been beaten, shot and set on fire.A third suspect, Alisa Campos, was charged with first-degree murder in the death Monday.
Prosecutors say Arellano was accosted by members of the Latin Kings street gang, who attacked him when he refused to give the gang hand signal. The gang members reportedly beat him with baseball bats, struck him with a car and finally shot him in the head.
His body was then set on fire and left in a gangway between two buildings.
The Associated Press contributed to this report.