Police patrol at Hollywood Boulevard and Highland Avenue on Wednesday.… (Luis Sinco / Los Angeles…)
The rallying cries shot out across Twitter and Facebook on Tuesday evening.
"Take the riot to Hollywood," one expletive-laden message on Twitter beseeched. "Hollywood. 7:30."
That invitation for trouble and others like it, police believe, were the seeds of a bizarre, chaotic night in the city's entertainment mecca that caught the LAPD off guard and left city officials scrambling to assure tourists and revelers, once again, that Hollywood is a safe place to be.
A group of 40 to 50 people, mostly teenagers, heeded the social media calls and went on what police described as a rolling crime wave.
LAPD Cmdr. Andy Smith said it appears the group thought Hollywood would be an easy target because police were focused on patrolling the Crenshaw District, which had been the scene of renegade violence during protests over the George Zimmerman verdict in Florida on Monday evening. As the problems began in Hollywood, the department was also dealing with protesters marching through downtown.
"What we're thinking is these youngsters took advantage of our redeployment of officers down to the Crenshaw District last night and decided that this would be a good night to come up to Hollywood and act a little crazy," Smith said.
So-called "flash mob" crime rampages organized through social media have been a problem in other cities, including Chicago, Philadelphia and Washington. In April, 28 Chicago youths were arrested on suspicion of attacking pedestrians along the city's famed Magnificent Mile. Illinois Gov. Pat Quinn signed legislation in May enacting stiffer penalties for people who text or use social media to organize mob attacks.
Until now, flash mob crime incidents have not been a major problem in Los Angeles, LAPD officials said.
The problems began shortly after 8:30 p.m. Tuesday, when 911 dispatchers started receiving reports of problems on Hollywood Boulevard near Vine Street — a stretch full of restaurants, clubs and shops. A group of a few dozen young people, callers said, was running in and out of traffic, knocking people over on the sidewalks and snatching their belongings. Some stole food and souvenir tchotchkes from stores as they went.
The fast-moving group moved east along the boulevard, and the calls for help kept coming. Responding officers were flummoxed by the mob, which splintered and scattered in different directions when confronted, only to come back together and then divide up again. Police officials hurriedly sent more than 100 officers from elsewhere in the city to Hollywood.
A strange game of cat and mouse ensued for the next few hours as cops searched for suspects over a large area stretching from Highland to Western Avenue.
In the end, 12 people were arrested on suspicion of robbery — 11 juveniles and one 18-year-old man. All of those arrested, police said, lived in South L.A. neighborhoods.
Police sources said many of those involved in the mob appeared to have arrived in Hollywood on the subway.
On Wednesday, detectives began the arduous process of collecting and combing through footage from the area's ubiquitous security cameras in an effort to identify others in the group who escaped.
Investigators were looking into the possibility that the group included people who participated in the Crenshaw violence and an earlier episode in Hollywood on Sunday night.
The upheaval took place against the backdrop of several days of protests against the acquittal of George Zimmerman, a former neighborhood-watch volunteer who fatally shot unarmed teenager Trayvon Martin in Florida.
Police sources who requested anonymity because of the ongoing investigation said they had uncovered Twitter messages from days before the Zimmerman verdict, in which people were discussing the idea of going to Hollywood to cause trouble. The acquittal, however, seems to have given the group a cause celebre and motivated more people to join.
"They're using Trayvon as an excuse," one police official said. "They were saying, 'Let's go mess up Hollywood for Trayvon.'"
City Councilman Mitch O'Farrell, who represents Hollywood, said that "what happened last night had nothing to do with honoring the memory of Trayvon Martin. Everyone knows that."
O'Farrell also described the turmoil Tuesday as "an anomaly" and sought to calm jittery nerves about safety in Hollywood — a vital neighborhood for the city that attracts hundreds of thousands of tourists each year, which has undergone a painstaking rehabilitation over the last decade from its past as a blighted and dangerous wasteland. The violence was the second time in recent weeks that Hollywood has grabbed headlines for the wrong reasons. Last month, a woman was fatally stabbed by a homeless man when she refused to pay him for taking his photograph.