Barbara Schmidt keeps a box of newspaper clippings under her bed. It’s a cheap plastic container with a light-blue lid. She rarely opens it. The photocopies inside, some of them labeled in her tidy script, are cut into rectangles of various sizes, neatly trimmed to frame the only story on the page that she cared about—that of her husband’s arrest, trial, and conviction for attempted murder in Lafayette, Louisiana, more than two decades ago. She isn’t sure why she clipped the articles in the first place, or why she still stores them within arm’s reach. “I just felt compelled to do it,” she says. One thing she’s always been sure about, though, is her husband’s innocence. She is like a mama bird: petite, protective of her family, loyal to her mate. “I chose to stay,” she says.

Just off Barbara’s kitchen is the room that her husband, a gastroenterologist named Richard Schmidt, used as his study before he went to prison. For her, this is where the story begins. On a hot July day in 1995, she came home to find several plainclothes police officers rummaging through Richard’s papers. She asked what they were looking for. “Evidence of B12,” she remembers them saying, with no further explanation. She called her husband at work to find out what was going on. The investigators had showed up there too. “He seemed clueless,” she recalls.

It didn’t take long for all the sordid details to emerge. The police were investigating a complaint by Janice Trahan, a nurse who had worked at Schmidt’s practice and had a decade-long affair with the doctor. As Trahan later testified in court, Schmidt had entered her house on the night of August 4, 1994, soon after she’d ended their relationship. She and her 3-year-old son were asleep in bed. Schmidt had woken her up, saying he wanted to give her a vitamin B12 shot, something he’d occasionally done during their relationship when she wasn’t feeling well. Trahan protested. Schmidt insisted. He pushed the needle into the muscle of her upper arm, depressed the plunger, and quickly left the house. Several months later, Trahan started feeling ill and was eventually diagnosed with HIV. She believed that Schmidt, in a fit of jealousy, had injected her with tainted blood from one of his patients.

Barbara has a different recollection of August 4, 1994, one she described to both the police and later the jury at her husband’s trial. The family had recently returned from a trip to Florida, she says, and Richard had injured his back lifting heavy luggage off the carousel. A record in her checkbook reminded her that she’d gone out to buy new knobs for the kitchen cabinets that day, which she had to show him as he lay in bed. “He wasn’t crazy about them,” she says. After that, Barbara maintains, she showered and they both went to sleep. (The Louisiana Department of Corrections declined to make Richard Schmidt available for an in-­person interview.)

When the police searched Schmidt’s office, however, they found something strange. Buried beneath a mound of old files was the notebook in which his nurses had recorded the previous summer’s blood draws and other lab work. Curiously, the notebook was only half full. The final entry showed that an HIV-positive patient had come in for an appointment on August 4. He had been scheduled for a blood draw, but the notebook didn’t confirm whether it actually took place. The police theorized that Schmidt had taken his patient’s blood, with or without the help of a conspiratorial nurse, and kept the vial hidden so he could use it on his former lover. Still, the evidence was circumstantial. One of Schmidt’s nurses, in her testimony, described the notebook as “just a jot sheet,” not an official record. The prosecuting attorney, Keith Stutes, needed harder proof.