Struck down at an office holiday party, almost all the victims of the mass shooting Wednesday in San Bernardino, Calif., were friends and colleagues. And in a notable difference from some other highly publicized rampages, some of them also knew their killer, Syed Rizwan Farook, who opened fire on the group with his wife, Tashfeen Malik, the authorities said.  Nicholas Thalasinos, 52, one of the victims, and Mr. Farook were part of the same “little group” of employees, his wife, Jennifer Thalasinos, said on Thursday. She said she had never heard her husband say anything negative about Mr. Farook during the time they worked together.  Ms. Thalasinos said that she and her husband were Messianic Jews, a faith that incorporates elements of Judaism and Christianity, and that her husband wore traditional Jewish tzitzit over his pants. He enjoyed talking about politics, his wife said, and he was not shy about expressing his views.  The coroner’s division of the San Bernardino County sheriff’s office identified those who died on Wednesday.  “My husband was very outspoken about ISIS and all of these radicalized Muslims,” she said, adding, “If he would have thought that somebody in his office was like that, he would have said something.”  A friend of Mr. Thalasinos’, Kuuleme Stephens, 41, said that during a phone call with Mr. Thalasinos while he was at work two weeks ago, she overheard him arguing about Israel with Mr. Farook.  “It wasn’t like he was shouting,” Ms. Stephens said, noting she did not think much of it at the time. She said she could hear Mr. Farook saying Israel was not the Jewish homeland and that Jews did not belong there. She said it was not out of the ordinary for Mr. Thalasinos to argue about politics and she thought this was just another heated debate.  “Nicholas always talked politics, and it seemed like just another passionate conversation about politics,” she said.  The authorities said on Thursday that the majority of the victims of Wednesday’s rampage, at the Inland Regional Center in San Bernardino, were employees of a division of the San Bernardino County Department of Public Health responsible for inspecting everything from restaurants and public pools to tattoo parlors. So was Mr. Farook, who left the party in a foul mood on Wednesday morning and returned soon after with Ms. Malik and an arsenal that included firearms and homemade bombs.  One of the only victims who did not work with Mr. Farook was Daniel Kaufman, 42, who ran the coffee shop at Inland Regional where he trained developmentally disabled people. Friends remembered him as a man of boundless enthusiasm and joy.  For more than a decade, he took part in an annual springtime Renaissance fair in Southern California, they said, lofting banners through the air and spinning around at the rear of processions that escorted the fair’s nobility through the grounds. He had a sixth sense for when a friend needed an extra hug.  “He was so full of life it was ridiculous,” said Stachia Chadwick, who knew Mr. Kaufman for over 10 years through the fair.  A deputy director of the environmental health department, Damian Meins, 58, was also killed. The Press Enterprise reported that he used to dress up as Santa Claus and take pictures with children at a local school, St. Catherine of Alexandria, where he had also worked as a physical education and after-school teacher. His wife, Trenna, is a principal at a different Catholic school, and they had two grown daughters.  “He was very funny, with the best sense of humor of anyone I know,” said Dottie Merki, a former co-worker of Mr. Meins’s at the Riverside County Department of Environmental Health, where Mr. Meins worked until 2010.  Times readers responded by the thousands to a simple question: How often, if ever, do you think about the possibility of a shooting in your daily life?  A number of victims left behind young children. Michael Wetzel, 37, had six, according to The San Bernardino County Sun. His church and a local parenting blog each started online fund-raisers for his family.  The Facebook page for Robert Adams, 40, another co-worker and victim, shows several photos and videos of him playing with a smiling young girl. “A little daddy daughter time,” he wrote beneath one picture of the girl laughing in a swing, her ponytails flying in the breeze.  He recently posted a quote from Albert Einstein to his profile: “The world is a dangerous place not because of those who do evil, but because of those who look on and do nothing.”  Bennetta Bet-Badal, 46, grew up in Iran but fled to the United States to escape the persecution of Christians under its Islamic regime when she was 18 years old, according to a fund-raising website set up to provide for her three children after the shooting.  She landed in New York but made her way to California, where she studied chemistry at California State Polytechnic University, Pomona, and married a police officer. She had three children ages 10, 12 and 15.  She loved her job as an inspector with the county’s public health department, according to the fund-raising site. On the day of the shooting, she left home excited for a presentation she was planning to deliver at the department’s annual meeting, an event that included the holiday party.  Tina Johnson, the ex-wife of Shannon Johnson, another victim, said Mr. Johnson had grown up around the South, and played college baseball for Augusta State University in Georgia. She said he loved animals so much they had a “menagerie” of pets, including iguanas, dogs, finches and a cat.  They mostly lost touch after their marriage ended after six years, and Ms. Johnson said she did not know exactly when he moved to California.  “He was a really good man with a really big heart,” she said. “I’m still kind of reeling.”  The health department’s losses went on. Two of the youngest were Yvette Velasco, 27, who painstakingly examined restaurants for health code violations, and Sierra Clayborn, 27, whose sister, Tamishia Clayborn, mourned her on Facebook: “RIP baby sis I love you more than you ever knew,” she wrote. “You were taken too soon.”  A woman who answered the phone at the home of Isaac Amanios, 60, the oldest victim, said he had a wife and three children. She said she was a relative of Mr. Amanios but declined to say more, except that the family was devastated. (Nat Berhe, a football player for the New York Giants, said on Twitter Thursday that he was a cousin of Mr. Amanios and that “he was so sick right now.”)  “All we know,” said the relative, “is we lost a brother, we lost a friend, that’s all.”  An earlier version of this article misidentified the college attended by one of those killed, Bennetta Bet-Badal. She attended California State Polytechnic University, Pomona, not California Polytechnic State University, which is in San Luis Obispo.  Reporting was contributed by Jess Bidgood, John Corrales, Jennifer Medina, Katie Rogers, Rick Rojas, Marc Santora and Daniel Victor. Susan C. Beachy and Kitty Bennett contributed research.  A version of this article appears in print on December 4, 2015, on page A24 of the New York edition with the headline: They Shared Their Working Hours, and Their Dying Moments . Order Reprints| Today's Paper|Subscribe
A day after 14 colleagues in a county health department were murdered at their office, family and friends tried to make sense of a devastating loss.