Another morning stuck in a conference room, another requisite all-staff meeting, and Patrick Baccari arrived to find his co-worker Syed Farook sitting at a table by himself. He was wearing a button-down shirt and a long beard. Baccari walked over to join him. “Ready to be bored?” Baccari asked, because that was always their joke. San Bernardino County required its health inspectors to gather at least twice each year for a day of speeches and continuing education. “I’m ready,” he would remember Farook telling him and smiling back.

They sat together near the back of the room as it filled with 75 people, and soon their table was full, too. There was Chris Nwadike, a government worker for the past 25 years. There were Isaac Amanios, a 60-year-old father of three, and Denise Peraza, 27 and newly married.

A technician wheeled out a lectern. A supervisor stood up to welcome them. At some point after the first hour, Farook got up and left his papers on the table and his jacket on the back of his chair.

“Where’s Syed?” Baccari remembered someone at the table asking, and then a little while later Farook was back, this time with his wife, two assault rifles, two handguns and hundreds of rounds of ammunition.