A dirty job at L.A. County’s Hall of Justice

Cops and prosecutors are returning to the scene of the grime.

But things will be brighter when the former occupants of the Hall of Justice move their offices back into the downtown Los Angeles landmark.

Work crews making seismic repairs to the building next month will begin blasting away 88 years’ worth of soot, dirt and smog that have turned its exterior a dull, dirty gray color.

When they finish this fall, project managers say the 14-story beaux-arts building will glisten as brightly as the slightly newer Los Angeles City Hall, which is diagonally across the street.

And why shouldn’t it? City Hall was built in 1928 from the same Sierra white granite from a quarry north of Fresno that was used in 1925 for construction of the Hall of Justice.

Often used as a backdrop in crime movies and old television series, the hall was home to the Los Angeles County Sheriff’s Department and the district attorney’s office.

It also housed the county coroner’s office, where the autopsy of actress Marilyn Monroe in 1962 concluded that she had committed suicide and the examination of presidential candidate Robert F. Kennedy showed he died of bullet wounds after being shot at the Ambassador Hotel the night of the California primary in 1968.

The trial of Kennedy’s killer, Sirhan Sirhan, was conducted in one of the hall’s 17 courtrooms. So was the trial of serial killer Charles Manson, who was held in one of the hall’s 750 tiny cells until he was convicted in 1971 and sent to state prison.

Manson later characterized the hall’s lockup as “stone age.” The office of his chief prosecutor, Vincent Bugliosi, was a few floors beneath Manson’s cell. In his book “Helter Skelter,” Bugliosi described its decor as “1930s Chicago.”

“The courtrooms in that building looked like old-time courtrooms,” recalls Encino criminal defense lawyer Donald Calabria, who worked in the hall as a public defender starting in 1969. “They had real substantial wood walls, not the cheap-looking ones” found across the street in the newer Criminal Courts building.

Construction crews have removed asbestos, lead and other hazardous materials from the hall as part of the $234-million seismic renovation stemming from the 1994 Northridge earthquake.

Most of the jail cells were ripped out and sold to a recycler for $450,000, according to James Kearns, assistant deputy director of the county’s Department of Public Works, which is overseeing the repair project.

But Manson’s old cellblock was preserved and will be part of an interpretive display that will tell the history of the hall and the project to save it, said Kearns, who stepped into Manson’s cell to demonstrate how the lockup’s barred doors still slam shut with a rumble and a chilling clank.

The old building has plenty of history, according to Sandi Gibbons, public information officer for the district attorney’s office who first went to work there in late 1965 as a courts reporter for City News Service. “I’ll tell you what they should put in there: the drinking fountain that a TV cameraman knocked off the hallway wall when they were bringing [Manson family member] Susan Atkins into the grand jury room. There was water everywhere. They put a steel band around it when they bolted it back on the wall,” Gibbons said.

Kearns said one of the hall’s courtrooms has been preserved as a Sheriff’s Department conference room, and a wood-paneled law library will also be turned into a meeting room. The sheriff will share the hall’s 400,000 square feet of space with the district attorney when the two departments move back inside after repairs are completed Dec. 31, 2014, Kearns said.

The building’s makeover — about 30% completed — includes construction of a parking structure next to the 101 Freeway that will have five levels underground and four above.

The hall’s three entrances will lead to a multistory loggia that retains its original marble flooring and staircases, along with a bank of ornate, wood-paneled elevators. They will be re-engineered and automated; in the past, elevator operators were required. In 1990, one of the operators was crushed to death when she was caught between a descending elevator and the 10th floor.

The refurbished building will be air conditioned for the first time. As originally designed by Allied Architects, the hall featured twin 14-story light wells that allowed every office to have an operable window for fresh air. In its new configuration, the bottom of one of the wells will be landscaped and will serve as an eating area for a new cafeteria being built on the ground floor, Kearns said.

But it will be the strikingly bright new granite facade that will be most visible for those working in the downtown area or passing by on the freeway. Diesel soot, dust and automobile exhaust have contributed to the darkening of the Sierra white granite over the decades.

Workers experimented on sections of the hall’s Broadway side with chemical dirt removers, high-pressure water cleaning and several micro-abrasive systems before settling on a bead-blasting technique, which relies on a combination of crushed recycled glass and tiny stones and is more gentle to granite, said Jeff Caldwell, an exterior forensics expert with the consulting firm of Wiss, Janney, Elstner Associates.

Because recent rains have washed dust and dirt from the upper levels down to the white test areas, those clean sections are already getting dirtier and darker, Caldwell said. That’s why cleaning crews on scaffolding will start at the top and work their way down, he said. There is terra cotta in addition to the granite on upper levels of the hall.

Greg Zinberg, project executive for Clark Construction, the main contractor for the county, said the Hall of Justice will shine bright — but it better last a while.

“This one might not be cleaned for another 50 years,” he said.

bob.pool@latimes.com