According to LAPD spokesperson CMDR. David Kalish, the police were forced  to declare the gathering an unlawful assembly due to violent outbreaks in the crowd attending the concert. Kalish stated at a press conference Monday night that concert goers and protesters were throwing rocks, bottles, pieces of asphalt at police on the scene. He also reported that several fires were started near the protest site and several individuals were attempting to breach the security fence around the Staples Center. It has been reported that is was approximately 300 of an estimated crowd of 8000 who resorted to violent behavior during the protest concert. 

At 8:00 the police declared the protest concert an unlawful assembly, pulled the power from the stage while the second band, Ozomatli , was playing. At that time the police asked those present to leave the area. At 8:20, 400 LAPD officers were sent in using pepper spray and rubber bullets to break up the remaining crowd. 

CMDR Kalish reported that 10 individuals were arrested as a result of the incident bringing the total arrest for Democratic National Convention related protest up to 38.  Kalish told reporters that many of the protest around the convention have gone off peacefully and lawfully and that the police were forced to break up this gathering when the attendees became violent. CNN reports that at least four people were injured during this incident. 

No statement was available from Rage Against the Machine or the protest concert organizers at Press time.