If the above pictures were of the same person, then he can be described as an agent provocateur at Bersih 3.0 rally.
In any case, while the police are busy trying to nab those shown to have flouted the law on that day, wouldn't it be better if they show the same diligence in calling up those policemen who had openly assaulted some unfortunate participants who happened to be caught by them?
According to Wikipedia:
"Traditionally, an agent provocateur (plural: agents provocateurs, French for "inciting agent(s)") is an agent employed by the police or other entity to act undercover to entice or provoke another person to commit an illegal act. More generally, the term may refer to a person or group that seeks to discredit or harm another by provoking them to commit a wrong or rash action."
"As a known tool to prevent infiltration by agents provocateurs, the organizers of large or controversial assemblies may deploy and coordinate demonstration marshals, also called stewards."
"An agent provocateur may be a police officer or a secret agent of police who encourages suspects to carry out a crime under conditions where evidence can be obtained; or who suggests the commission of a crime to another, in hopes they will go along with the suggestion and be convicted of the crime."