Jones was angry at Barnes for not showing him any respect, according to Assistant District Attorney Vincent Furlong.
During a preliminary hearing, Correctional Officer Denard Craighead testified that he saw Jones stab Barnes repeatedly in the exercise yard and the day room at the prison.
Defense attorney Gerald A. Stein later called Barnes as a witness.
"Did Aaron Jones stab you?" asked Stein.
"No," replied Barnes. "I don't know who did it."
Barnes said he was too "dizzy" to know who had assaulted him as he ran bleeding from the exercise yard to the day room.
The exchange infuriated Furlong, who argued that Barnes had been intimidated by Jones and was too frightened to implicate him.
"He was not intimidated by me," said Jones.
Furlong said that shortly after the incident, Barnes told police that Jones was the assailant.
The prosecutor said Jones "thinks he's above the law. He has no respect for the law. Aaron Jones is a very dangerous man."
Furlong won a bail increase in the case from $25,000 to $500,000 after revealing that Jones already was being held under $5 million bail for repeatedly shooting convicted drug dealer Richard Isaac on Feb. 21.
Jones is second-in-command of the JBM, a violent drug gang, according to testimony by a police detective at an earlier bail hearing.