War and Peas by Jill Churchill

works is that you pour loose gunpowder down the barrel and then ram a round lead bullet wrapped in a piece of cloth down on top of the powder. Then you put a small copper percussion cap containing a mercury fulminate on a nipple under the hammer. When the hammer falls, it detonates the mercury fulminate and a flame flashes through a hole in the nipple into the rear of the barrel. That sets the gunpowder off and sends the bullet on its way.“
    “So if you don’t know how much gunpowder the murderer used, you can’t tell how hard the gun shot, so the modern formulas don’t work?“ Shelley asked.
    Jane looked at her with amazement.
    Mel nodded. “Exactly. And they don’t know much about spherical lead bullets anymore, either.“
    “I thought things were supposed to be simpler in the olden days,“ Jane said.
    “They probably were,“ Mel said. “A modern firearm is a lot more complicated. You just don’t have to know as much about it to fire it. Think of them as more ‘user-friendly.’ “
    “But only a ‘gun nut’ would know how to fire the old one,“ Jane said.
    Mel shook his head. “You’d be surprised how many people know about guns. Anyone who works in a museum, probably. And a lot of other people, too.“
    “What about the second reenactment?“ Shelley asked. “The one that was filmed.“
    “No help at all. And before you ask, we’ve run down nearly everyone who was watching the first time and nobody had a video camera. One woman had a still camera and took a few pictures, but they’re all of the soldiers, not the civilian reenactors.“
    “Go back to the gun,“ Jane said. “Could it have been fired from the woods instead of on the field?”
    Mel nodded. “Afraid so. And nobody admits to having been in the woods except the reenactors, if that’s the next question.“
    “It was. What about the museum case the gun was in?“
    “No fingerprints whatsoever. A few fibers of paper towel stuck in the edges. Somebody went to considerable lengths to clean it up. And that might not have been deliberate. The volunteers say they often go around with a glass cleaner and paper towels when they’re not guiding tours. With so many cases and so much glass, it’s a constant job. One of the tour guides thinks she might have cleaned that case last Friday, but can’t remember if the gun was in there or not. She had no reason to pay attention.“
    “Doesn’t firing a gun leave powder on your hands?“ Shelley asked.
    Mel nodded. “It does. But by the time we had an idea of what had happened, almost all the museum people who participated had gone to that mobile home, taken showers, washed their hair, and so forth. We didn’t even test anyone. If we’d tried to bring in a case on the basis of traces of gunpowder, we’d have been laughed out of court. Everyone who participated probably had some powder on their clothes and hands.“
    “So much for science,“ Shelley said. “What about alibis?“
    “Just as bad,“ Mel said. “Babs, Sharlene, Lisa, and Tom Cable were right there on the field. No alibi at all, but all four of them didn’t do it. Georgia says she was buying cotton candy, which seems so out of character that I almost have to believe her. Derek says he was in the museum’s mobile home by himself. He didn’t like admitting it. I think he was up to something he shouldn’t have been, like pawing through the women’s clothes left in the mobile home. Or maybe he’s lying.“
    “What about Caspar Snellen?“ Jane asked. “Vague. Looking around the fair,“ Mel replied. “Could be true.“
    “And Whitney Abbot?“ Shelley asked sharply.
    Mel smiled. “Your personal favorite, I take it?”
    Shelley shrugged.
    “Says he arrived a few minutes before the reenactment, but had misunderstood the time it was to happen and sat in his car doing some paperwork. Had the engine running, windows up, and air-conditioning on full blast. Says he didn’t even hear the battle. Claims the first he knew