click to enlarge Noah Berger/Reuters

An undercover CHP officer brandishes a gun at protesters in Oakland, while his partner makes an arrest.

#OaklandProtests If allegation officers incited crime, crowd source video & provide a link so I may forward. Obviously troubling. — Lt. Chris Bolton (@OPDChris) December 11, 2014

We got a first-hand account from Michael Short, an Oakland-based freelance photographer who was taking pictures for thelast night. Read it below.In a press conference with reporters, CHP Golden Gate Division Chief Avery Browne said that the agency routinely deploys plain-clothed officers to gather intelligence on the protest, while monitoring Twitter feeds for information on march routes, planned freeway takeovers, and possible officer attacks.The man who sucker-punched the undercover CHP officer was booked in Santa Rita Jail on felony assault and officer battery charges, Browne said. Only one other arrest was made last night for public intoxication.A plain-clothed California highway patrol officer brandished a gun at protesters in downtown Oakland last night, in what quickly became the defining image for a week of civil unrest.According to Oakland Police spokesman Frank Bonifacio, the incident happened at Bay and Harrison Streets, near Whole Foods. Images captured by Reuters photographer Noah Berger show two men — apparently undercover CHP officers — making an arrest while a small throng of demonstrators gathers around them. One man, wearing a Black Bloc-style face mask, is tackling a suspect, while the other is aiming his gun at the crowd.Photographer Michael Short, who was covering the protest forlast night, tellsthat the incident happened close to midnight. At that point the protest — which had begun with a crowd of about 200, in Berkeley — had dwindled to about 75 people. They were marching up 27th Street when a group in the front suddenly started yelling about an undercover cop infiltration."These two stockier guys started backing away from the group," Short recalls. Initially, he says, both had masks on, though at some point the man brandishing the gun in the photo took his mask off. Someone in a trench coat sucker-punched the other agent from behind, and a scuffle ensued. At that point, the unmasked officer pulled out a spring baton and a gun, yelled at everyone in the crowd to retreat, and radioed for backup."The consensus was that they were cops, and people seemed to know it," Short says, adding that he doesn't recall either officer drawing a badge or identifying his credentials. Short didn't see the cops engaging in vandalism, though he had seen windows broken at a Chase Bank and a T-Mobile store earlier in the evening. He'd also had to fend off angry demonstrators who surrounded him when he tried to take pictures.Still, reports of the CHP officers' behavior created an uproar on social media. Within hours, Berger's pictures had gone viral, leading to speculation that the CHP patrolmen were actually agent provocateurs, deployed to incite the crowd. OPD lieutenant Chris Bolton responded on Twitter: Bolton confirmed via Twitter that the two officers pictured are indeed from the CHP, and Oakland police are referring all press inquiries to that agency for comment. We have yet to hear back from a CHP spokesman, but we'll keep you posted.