That’s when the heavy lifting began, literally. In a blog post describing the evolution of the project, California Watch’s editorial director, Mark Katches, explained that:

[Johnson’s] desk soon became cluttered with reams of documents, forming a fortress growing higher and higher. Tens of thousands of PDF files about earthquake safety in California’s public schools soon taxed his laptop hard drive. The documents painted a disturbing picture of a system of oversight in disarray.

For months, Johnson worked on the story alone in our Sacramento bureau under the supervision of his editor, Robert Salladay. He became a virtual embed at the Division of the State Architect. Routinely, Johnson hauled our 30-pound copy machine several blocks to make copies - cutting down on copying costs. He filed regular blog posts for us, but his first real story would need more time.

The extra time would pay off. By early 2010 Johnson had revealed that the regulatory apparatus governing seismic safety in schools had clearly broken down, but that alone was not enough to satisfy him. He wanted to know why it had broken down, so he kept digging.

In June 2010 Johnson was working in the library of the Division of the State Architect when he noticed a binder marked “policies and procedures.” In it he discovered that California keeps confidential evaluation records for a network of 1,500 specially trained seismic safety inspectors hired by school districts to vet building projects. Johnson had to fight for months to get them, going back and forth with state officials and their lawyers, eventually convincing them that they had no right to keep the ratings confidential since the inspectors are not state employees. Once in hand, the records showed that nearly 300 inspectors had been cited by the state for work-related deficiencies, even though at least two-thirds were allowed to keep monitoring school construction jobs. Multiple inspectors had been accused of filing false reports with regulators and failing to show up at critical moments during construction jobs, yet the state had done little to nothing to reprimand them.

“These records had been very tightly held, and finding them was a result of being at the library, looking over my shoulder, and just happening to spot this dusty binder,” said Johnson. But the discovery had consequences.

“Naturally, the day I asked to copy those policy documents was the last day they let me in the library. Once they saw that I’d grabbed that off the shelf they said, ‘We have to renovate the library,’ and ended up putting me right around the corner from a bathroom, totally away from anybody and anything. And that’s when they assigned a person to watch me every day.”

Indeed, Johnson says the state’s minder was tasked with not letting him out of her sight, and officials at the Division of State Architect began making him jump through other hoops as well. They insisted, for instance, that he travel to its Los Angeles offices to view records that should have been easy to send north, and that the minder accompany him along the way. “That’s kind of how it went for months, those kinds of games,” Johnson said.

Things really came to a head in the late summer and fall of 2010. In July, Johnson obtained names of state employees that were members of a lobbying group, the Coalition for Adequate School Housing, which had repeatedly pushed for less regulation and oversight of school construction. State officials denied that any employees belonged to the group, but were forced to “backpedal” when Johnson pulled out a list at a meeting showing that several top managers at the Division of the State Architect were indeed members (other records showed that regulators were even told that taxpayers would reimburse their membership dues).

Johnson pulled off his most impressive feat of reportorial prowess in November, however, when he convinced a source in the Division of the State Architect to give him a hard drive with years of e-mails, memos, reports, surveys, policy drafts and directions, and other confidential records relating to the regulation of seismic safety across various agencies. Katches, California Watch’s editorial director, called it a “treasure trove,” which revealed that for years officials across state government had been aware of school construction problems, but failed to address them.

Johnson had to follow a circuitous route to get the hard drive. By that point in his investigation the state and basically clammed up on him. “They were aware that I was this bugaboo burrowing down for information,” he said.

Curtis Brainard writes on science and environment reporting. Follow him on Twitter @cbrainard.