Copyright The Boston Globe

Police said they were investigating the crime alongside the FBI’s Art Crime Team, which is tasked with probing all art-related matters, “in this case, antiquities and cultural property trafficking.” The investigation has not yet yielded any leads, Lori Fogarty, the museum’s director, told The Washington Post on Thursday. She said authorities believe that the burglary was a “crime of opportunity” in which the perpetrators had no specific target but instead grabbed anything they could. There’s no indication that any museum employees were involved in the crime, Fogarty added. The robbery occurred just before 3:30 a.m. on Oct. 15 — four days before the brazen daytime theft of French crown jewels from the Louvre museum in Paris. It took museum personnel days to get a full inventory of what was stolen, Fogarty said. Aside from the metalwork and artifacts, Fogarty said a “large portion” of the missing items are historical memorabilia — such as political pins, awards, and athletic trophies — that serve the museum’s mission to “tell the broad story of California.” “The harder part is to place a value on it, because a lot of these objects are historical memorabilia that we’ve had for decades, so there might not be current appraisals or values identified,” Fogarty said. “So that is a part we’re still working on.” The museum initially kept news of the burglary quiet, following guidance from Oakland police and federal investigators meant to avoid compromising the early days of the investigation, Fogarty said. “This material may end up in a pawn shop or a swap meet or an antique store where a member of the public could see them,” she said. “So it was really at a point in the investigation that they determined, ‘Let’s get the word out and let the public help us.’” The museum had previous on-site burglaries in 2012, when Gold Rush-era pistols were stolen, and 2013, when a gold jewelry box disappeared. Andre Taray Franklin was sentenced in 2014 to four years in prison after pleading guilty to selling the box, which was later recovered from a local business, the US attorney’s office for the Northern District of California said at the time. The museum strengthened its security measures after those incidents, Fogarty said. Since the Oct. 15 burglary, she said, the museum has also tightened security at its off-site facility, whose location it has declined to identify. Museum officials are considering additional measures to prevent unauthorized access in the future. The theft of the artifacts is a “devastating and heartbreaking loss” for the museum, which is home to more than two million objects, Fogarty said. “We are very committed to doing everything we can to identify the thieves,” Fogarty said, “but most importantly, bring this work back to the museum.”