"These individuals are responsible for tags not only in Los Angeles but Las Vegas and San Francisco,” said Sheriff’s Cmdr. Dan Finkelstein, who is chief of the Metropolitan Transit Authority police. “The Army Corps of Engineers estimates that removing the "MTA" tag from the riverbed alone will cost $3.7 million.

Those arrested were booked on suspicion of vandalism, drug possession, narcotics for sales, weapons possession and other parole violations, officials said

The arrests occurred during a series of early-morning raids centered in the Hollywood area. Among those detained for a parole violations is a famous tagger whose work “SMEAR” has has won acclaim in the art community.

Los Angeles County sheriff’s deputies today arrested at least eight alleged members of the notorious Metro Transit Assassins tagging crew, some of whom are believed to be responsible for a several-blocks-long “MTA” tag in the concrete Los Angeles River bed that authorities say will cost millions of dollars to remove.

Cleaning graffiti from the river is far more expensive than cleaning other areas. Officials use high-pressure water spray to remove the toxic paint.

But hazardous-materials crews must then dam and capture all the paint and water runoff to prevent it from getting into the river. The crew did an additional $20,000 worth of damage to transit vehicles and facilities. Finkelstein said the Los Angeles River "MTA" tag, in a vast industrial district east of downtown between two rail yards, took about 400 gallons of paint -- 300 gallons white and 100 gallons black. “It took them four nights to do it,” he said.

The three block letters cover a three-story-high wall and run the length of several blocks between the 4th Street and 1st Street bridges. The tagging crew, which is also known as “Melting Toys Away” and “Must Take All,” began about the time the transportation agency began using the MTA letters. Investigators say they have statements, including some on video, that implicate some of the crew members in the enormous tag.

“Some of this group could face federal charges,” Finkelstein said. During the raids, Finkelstein said, investigators found customized high-pressure fire extinguishers that, when filled with paint, allow the tagger to hang upside down on the underside of a freeway and quickly scrawl massive graffiti. These taggers are not kids, he said.

Most those detained are in their 20s; one of them drives a $60,000 BMW, and another member possesses a diamond-and-ruby-encrusted Metro logo pendant with paperwork suggesting it's worth $29,000, Finkelstein said.

-- Richard Winton

Photo: Police car shows scale of the giant "MTA" tag in the Los Angeles River in May 2008. Credit: Al Seib / Los Angeles Times