Miss Hodges scraped a wooden match along the side of a matchbox. The tip of the match burst into flame. The teacher held up the match for the class to see.
“This,” she said, “is what we’re going to study today. Fire.”
She blew the match out, ran it under a faucet, and threw it away. “Why might a crime scene investigator need to know about fire?” she asked.
Ricky raised his hand. “To help him figure out who burned Rocky the Ram,” he said.
“So he can score some VIP football tickets,” added one of his pals, getting a laugh from his friends. “And share them with his best buddies.” Another laugh.
Miss Hodges smiled. “Yes, Ricky, that is one very specific reason why an investigator might need some knowledge of how fire works. Why else?”
Kayla raised her hand. “A criminal might burn down a building or something.”
“Good,” Miss Hodges said. “And what do we call it when a criminal burns something intentionally?”
“Arson?” Hannah guessed.
“Correct!” Miss Hodges said. She wrote the word on the dry-erase board. “In a suspected case of arson, forensic experts look for the answers to several questions. Did the fire start accidentally, or did someone set it on purpose? Where did the fire start? How did it start? And, of course, if it wasn’t an accident, who started it?”
Looking slightly puzzled, Corey raised his hand.
“Yes, Corey?” the teacher said.
“In this case, we already know the answers to those questions,” he said. “The firefighters started the bonfire on purpose at the high school with matches. I was there. I saw them do it.”
Other students murmured their agreement.
Miss Hodges nodded. “Yes, that’s true in this particular case. But today we’re talking generally about investigating crime scenes that have involved a fire. We’re not just talking about Rocky the Ram.”
She picked up her dry-erase marker again. “Let’s start with the basics. What do you need for a fire?”
Ryan, one of Ricky’s friends in the back of the class, spoke up. “Matches, wood, and maybe some lighter fluid.”
“Well, you’ve got the number right,” she said, tossing the marker in the air and then catching it. “You need three things. When it comes to fire, what is wood? Or coal? Or paper?”
“Fuel,” Ben said.
“Yes!” Miss Hodges said, writing it on the board. “Fuel! And when you touch a match to fuel, what is the match providing?”
“A flame?” Jennifer volunteered. She didn’t sound sure of her answer.
“What’s in that flame?” the teacher prodded. “Not cold, but . . .”
“Heat!” Jennifer cried with certainty.
“Exactly!” Miss Hodges said, writing “heat” on the board under “fuel.” “That’s two. And so there’s one more thing you need. What is it?”
Ben was about to speak, but Charlie beat him to it. “Oxygen,” he said. “Fire can’t burn in a vacuum.”
Everyone was amazed. Not that he got the answer right. Everyone knew he was smart. But that he’d answered the question out loud. Charlie never spoke unless he was called on. Was being partners with Ricky making him less shy?
“That’s my partner!” Ricky said, grinning proudly.
“Very good, Charlie,” Miss Hodges said as she wrote “oxygen” on the board. “So for a fire you need fuel, heat, and oxygen.”
She went on to explain some of the heat sources (matches, candles, cigarettes) and fuels (wood, paper, rags) an arsonist might use. These were items to search for at a burned crime scene.
She also told the class about accelerants—things that make a fire burn faster, like gasoline and kerosene. Sophisticated lab tests could detect traces of accelerants left at the scene of an arson.
“Now let’s return to one of those questions I asked at the beginning of class,” she said. “Where did the fire start? How might a CSI go about answering that question?”
“I’d search the burned building,” Ricky said.
“Looking for what?” Miss Hodges asked.
“The kinds of things you’ve been talking about,” he explained. “An empty gasoline can. A cigarette butt. A lighter.”
The three friends in Club CSI were impressed. That was a pretty good answer. Maybe hanging out with Charlie was rubbing off on Ricky.
“Good,” Miss Hodges said. “First you’d look for any obvious objects the arsonist might have used to start the fire. But some arsonists are clever. They don’t leave clues like that for you to find.”
She explained that fire can leave burn trails on floors for the investigator to follow. Fire can flake wood, with smaller particles toward the hottest part of the fire. That can be a clue about where the fire started.
Then Miss Hodges drew a V on the board. Since fire rises and spreads, she explained, it can burn a big V on a wall. “The bottom of the V points right to where the fire started,” she said.
“Now,” she continued, turning away from the board, “let’s imagine someone’s committed arson here in the lab. I’ve placed a few clues around the room. Please break into your teams and then see what you can find.”
There was a chaotic rush as the students found their teammates and started searching the room.
“A match!” Jennifer squealed. “I found a burned match here on the floor!” Miss Hodges reminded her to carefully note where she’d found the match and to pick it up with tweezers and collect it in a plastic bag.
By looking in the trash, Corey found an empty lighter fluid container. Ricky and Charlie found a small, dark V on the wall, hidden in a corner. The class agreed that the “fire” (if there had really been one) must have been started there with the match and the lighter fluid.
“Very good!” Miss Hodges said, gesturing for the students to return to their seats. “You’re turning into real investigators!”
Kayla raised her hand. “Miss Hodges, I have a question.”
“Yes, Kayla?” the teacher said.
“Why?” Kayla asked.
Miss Hodges looked puzzled. “You mean why are you becoming good investigators? You’re learning more every day.”
“No,” Kayla said, shaking her head. “I mean why would anyone commit arson? What does the criminal get out of it? Whatever someone burns is ruined, so it’s not worth anything.”
The teacher smiled. “That’s an excellent question, Kayla. What do you think, class?”
“Some weirdos just really love fire,” Ryan said. “They’re, like, obsessed with it.”
“That’s true,” Miss Hodges said. She wrote “pyromania” on the board. “Some experts think it might give them a feeling of power to start a fire. Why else might an arsonist start a fire?”
“Revenge?” Ricky said. “To get back at someone?”
“Yes,” Miss Hodges said, writing “revenge” on the board.
“Insurance fraud,” Corey suggested. He’d heard an uncle of his talking about a criminal burning down a building to get the insurance money.
“Very good,” Miss Hodges said, writing “fraud” on the board. “Now I’m going to write down another word. Can anyone tell me what it means?”
The class watched as she wrote “spoliation.”
Everyone was stumped. Even Ben and Charlie.
“Aha!” Miss Hodges said. “I’ve stumped you!”
“Spoliation,” Ryan said from the back of the room, “is when you spoliate something. My sister exspoliates her face every night.”
“I think you mean ‘exfoliates,’” Hannah said. “That’s when you scrub away the dead skin cells.”
“It doesn’t help her face any,” Ryan said, getting a laugh from his friends.
Miss Hodges rapped her knuckles next to the word “spoliation” on the board. She said, “‘Spoliation,’ as the term is used by forensic scientists, means the destruction of evidence. And sometimes spoliation is a reason for arson.”
“So the criminal starts a fire to burn up the evidence of some other crime he’s committed?” Hannah clarified.
“That’s exactly right,” Miss Hodges confirmed.
Ben raised his hand.
“Yes, Ben?”
“Is anyone thinking that’s what happened in the case of Rocky the Ram?” he asked.
Miss Hodges cocked her head, thinking. “I doubt it,” she said. “This wasn’t a case of arson. The fire was set carefully and safely by professionals. The only crimes here seem to be the theft and the destruction of the costume.”
“Maybe whoever stole the costume burned it to cover up the theft,” Corey said, thinking out loud.
“That doesn’t make any sense,” Ricky protested. He pretended to be the thief and said, “Oh no! I’ve accidentally stolen Rocky the Ram! I’d better burn him up!” Several kids laughed.
“I was just tossing out an idea,” Corey grumbled.
“Yeah, I think that’s the right thing to do with that idea,” Ricky said. “Toss it out.”
“We’re just about out of time,” Miss Hodges said. “Tonight I’d like you to read the section on fire forensics in your textbook. See if it gives you any ideas about the mascot case. I’d also recommend that you do a little research to see if any similar crimes have been committed in the past here in town. That’s one of the things a real CSI team would do at this stage.”
The bell rang, and the students headed out of the lab. As they went, one of Ricky’s pals joked, “Maybe there’s a serial mascot-costume burner on the loose in Nevada!”
His friends laughed, but Ricky didn’t. Ben suspected he and Charlie were going to do the research suggested by Miss Hodges.
Well, they wouldn’t be the only ones. . . .