by David Lewman
“But what about the broken dog biscuit?” Hannah pointed out. “And the shoe print?”
“May I see the biscuit?” Hannah’s mom asked. Corey dug the evidence bag out of his pocket and handed it to her. She held up the plastic bag and looked at its contents.
“I guess these could be crumbs from a dog biscuit,” she relented. “But they also could be from just about anything. And who knows how long they’ve been out in the yard?”
Ben could see Hannah was getting frustrated, so he spoke up. “We’ll have to analyze them in the lab to try to figure out what they are,” he said.
Mrs. Miller handed the bag back to Corey. “Might the shoe print be one of your father’s?” she asked.
“It didn’t look like it,” Hannah said. “We could compare the shoe print to one of Dad’s shoes.”
“We’ll have to wait until the plaster cast dries,” Ben reminded them. “Right now the shoe print is covered by the flour mixture.”
Hannah’s mom picked up the stack of missing dog posters. “Honey, I know you want to do your investigation. And I’m trying to support you with that. But I’d still like for you and your friends to put up these posters. Your dad and I think that’s our best chance of bringing Molly home.”
“But, Mom,” Hannah protested. “What if whoever lured Molly out of the house sees the poster? Instead of being punished for dognapping, they’ll get rewarded!”
“Hannah, enough,” her mom said firmly. “We all want Molly to come home. Please go outside and put up these posters.”
Hannah, Ben, and Corey walked down the front sidewalk from Hannah’s house carrying the posters. They also had a stapler, tape, nails, and a hammer.
“I still think this is a bad idea,” Hannah grumbled. “Claiming a reward may be exactly what the dognapper had in mind from the very beginning.”
“Maybe we should hang the posters in places no one will see,” Corey suggested. “Like on the bottoms of garbage cans.”
“I think Hannah’s parents would notice right away,” Ben said.
“Do they always go around looking at the bottoms of garbage cans?” Corey asked.
“I mean, I think they’d notice if they drove around their neighborhood and didn’t see a single poster,” Ben explained.
Ben secretly agreed with Hannah’s mom. He knew that offering a reward was a good way to motivate people to look for a missing pet. He didn’t want to tell Hannah he agreed with her mom, though, because he knew it would probably just upset her more.
Working together, they soon had put up a bunch of the posters on telephone poles. A few store owners let them put up the posters in their windows.
As they made their way around the neighborhood, they noticed that several of the houses had stickers in their windows announcing A DOG LIVES HERE. They were the same stickers given away at the dog contest, letting the fire department know which houses had dogs living in them.
They were heading down the sidewalk, looking for a good place to hang another poster, when they saw Lauren coming toward them wearing her big red sweatshirt. She was walking Princess on a pink leash.
“Hi, Lauren,” Corey said. He was never too shy to say hi to anyone whose name he knew. Ben envied him a little for that.
“Hello?” Lauren said. It was a question, not a greeting. It meant, “Who are you and why are you talking to me?”
Then Lauren recognized Hannah. “Oh, it’s you,” she said. “Don’t worry, Princess. She hasn’t got her nasty dingo with her.”
Before Hannah could say anything, Ben held up one of the posters in front of Lauren’s face. “Molly’s missing. We think someone took her.”
“Oh no,” Lauren said. “I am so sorry. That’s just awful.”
The words she said were nice, but the way she said them sounded totally fake.
Lauren and Princess walked on past them. “Hope you find your dingo,” she called back over her shoulder.
“Oh, we will!” Hannah said. “We will find my Australian cattle dog!”
Lauren just kept walking.
Chapter 8
Early the next morning Corey and Ben got to Hannah’s house before school. They were eager to see if the plaster cast of the shoe print had worked.
Hannah opened the front door and led them straight through to the backyard.
The plastic wrap was still covering the flour mixture. Ben carefully peeled off the plastic and touched the plaster.
“Feels dry,” he said. “I think it’s ready.”
He slowly lifted the piece of white plaster away from the ground. When he turned it over, they could clearly see the shoe print. They all grinned.
“Nice!” Corey said. “Even better than a dinosaur footprint!”
Hannah brushed dirt off the plaster cast and put it in a large plastic bag labeled “Shoe print.” “I can hardly wait to show Miss Hodges our evidence and hear what she thinks,” she said.
“Speaking of evidence, I thought of something else we should have collected yesterday,” Ben said. He walked over to the broken safety light and looked at the part of the light where the bulb screwed in.
“Just as I thought,” Ben said, smiling.
“What is it?” Corey said. “A confession?”
“The base of the broken bulb is still in the light,” he said. He put on his gloves and carefully unscrewed the metal base of the bulb from the socket. Then he put the broken piece into a jar he’d brought in his backpack.
“Good thinking,” Hannah said.
“Thanks,” Ben said. “And now I think we’d better get to school.”
Miss Hodges was busy that day, but Club CSI finally managed to get some time with her to share their evidence. In the forensic lab, they brought out their evidence: the broken glass, the crumbs, the plaster cast, and the base of the broken lightbulb.
“Wow,” she said. “I’m impressed. You’ve done a great job of gathering evidence.”
Hannah smiled. She was still terribly worried about Molly, but she liked Miss Hodges, so it always felt good to be praised by her.
Miss Hodges picked up the jar holding the pieces of broken glass. “Let’s begin with the broken glass,” she said. “You might remember from class some of the ways experts can analyze glass fragments.”
“They can look at the color,” Corey said quickly.
“That’s right,” Miss Hodges said. “And so can we.”
She laid a piece of black paper on a table. Then she opened the jar and carefully spread the pieces of glass across the paper.
“It looks as though all the pieces are the same color,” Ben said.
“Yeah, they’re all white,” Corey agreed.
“Yes,” Miss Hodges said. “And what does that suggest?”
“That they all came from the same lightbulb,” Hannah answered.
“Right,” Miss Hodges said. “Let’s take a closer look.”
Using magnifying glasses, they examined the pieces of glass. Some of the fragments had printing on them.
“Like the words you see printed on the top of a lightbulb,” Ben said. “The number of volts and the wattage.”
“The what-age?” Corey asked.
“Exactly,” Ben said.
“What do you mean ‘exactly’?” Corey said. “I’m asking you what ‘wattage’ is.”
“Oh,” Ben said, getting it. “Watts are a measure of how powerful an electric lightbulb is. The more watts, the brighter the bulb.”
“Oh yeah, I knew that,” Corey said. “I just don’t think I’ve ever heard anyone say ‘wattage.’ Wattage. The more you say it, the weirder it sounds.”
They compared the glass fragments to the small pieces of glass still stuck to the base of the broken bulb. They matched.
“It seems clear that these fragments are from the broken light you found,” Miss Hodges said.
Hannah thought of something. “Is there any way to tell from a broken lightbulb whether it was on or off when it broke?”
Miss Hodges nodded. �
�Yes, physical examination can reveal, in some cases, whether or not a lightbulb was on when it was broken. Why do you ask?”
“Well,” Hannah began. “My parents think I accidentally broke the light when I was taking the garbage out, while it was turned off. I think someone broke it after I came inside and turned on the lights. Proving that the light was on when it broke would support my theory that someone else came into my yard,” Hannah explained.
“Ben, pass me that base of the lightbulb. If the filament is still intact, we can examine it and possibly determine whether or not the light was on when it broke,” Miss Hodges explained as she looked carefully at the filament. After a few moments, she looked up, smiling. “Hannah, this is what investigators sometimes refer to as a ‘break’ in the case. Based on the condition of this filament, I can tell you with certainty that this light was on when it was broken.”
Miss Hodges went on to explain that because the filament appeared distorted and damaged, it meant that the light had been on. “This is some pretty advanced lab science known as ‘the tungsten trick,’ but in a nutshell, the condition of the filament helps determine if the light was activated or not when the glass enclosure, or the bulb itself, was shattered. If it looked shiny and smooth, it would indicate that the light had been off,” she told them.
Ben, Corey, and Hannah took turns looking at the filament closely. Ben made a mental note to research the tungsten trick to learn more about it.
For the first time since Molly disappeared, Hannah felt a little bit hopeful. “I can’t wait to go home and tell my parents!” she said excitedly.
“Hey, slow down,” Ben said, laughing. “We have some more evidence to get through.”
Miss Hodges smiled and picked up the bag of crumbs. “So, what do we think we have here?”
Hannah said, “Well, we’re not certain, but our theory is that they’re from a crushed dog biscuit and that it’s the same kind they gave out at a dog contest last weekend. Molly doesn’t like them.”
Ben threw up his hands in frustration. “Oh, I just thought of something! We should have brought one of those dog treats for comparison.”
Smiling, Hannah reached into her backpack and pulled out a plastic bag. She held it up for them to see. Inside was a bone-shaped dog biscuit.
“Brilliant,” Corey said. “You know what we should compare first? The color.”
Miss Hodges gave Corey a slightly suspicious look. She was starting to notice that color was always Corey’s first suggestion when it came to analysis.
When they compared the crumbs to the whole biscuit, all four of them agreed that the colors matched. There were a couple of big broken pieces whose shapes seemed to match up well with the whole biscuit.
Still, a lot of dog biscuits were the same color. And a lot of them were shaped like small bones.
“Hey, I’ve got an idea,” Corey said. “Let’s weigh the dog biscuit. Then we’ll weigh all the broken pieces together and see if the two weights are close.”
Miss Hodges nodded. “Corey, that’s an excellent idea. We’ll use the digital scales.”
The forensic lab had a small set of scales that could weigh objects very accurately, down to a fraction of an ounce. Using tweezers, they picked up all the crumbs from the plastic bag and put them on the scale.
Then they weighed the whole biscuit, and it only weighed a tiny amount more than the crumbs. “That makes sense,” Ben said. “We probably left the smallest fragments in the yard. We couldn’t get every single piece.”
“We used tweezers,” Corey pointed out.
“I mean, without using some kind of special collection tool, like a vacuum cleaner or something,” Ben explained.
“The point is, the colors match,” Hannah said. “The shapes seem to match. And the weight pretty much matches.”
“And the smell,” Corey added. “The crumbs smell like peanut butter, and so does the whole biscuit.” The others sniffed the dog treats and found that Corey was right.
“Could Molly have brought the treat into the backyard herself?” Miss Hodges asked.
Hannah shook her head firmly. “I offered her one right after they gave us the bag of treats at the dog show, but she didn’t like it. She just sniffed it and turned away. So I stuck our bag of treats in the cabinet.”
Miss Hodges picked up the plastic bag with the white shoe print cast in it. “And so we come to our last piece of evidence.”
She opened the bag and took out the plaster cast. Turning it over in her hands, she said, “This is an excellent cast. We haven’t even covered making these in class yet. How did you know how to do this?”
“Dinosaur Camp,” Corey said. The teacher looked puzzled.
“And I read ahead a little bit in our textbook,” Ben admitted.
Miss Hodges set the plaster cast on the table. “Well, you did a great job. Now let’s talk about shoe-print evidence. When we get to this part of our textbook in class, you three will be a little bit ahead of the game.”
She walked over to the dry-erase board and picked up a marker. “There are three basic types of shoe prints,” she said as she wrote them on the board. “Patent, latent, and plastic.”
“A person leaves behind a patent print,” she continued, “when they walk through something like paint or blood and leave visible prints behind.”
“So this shoe print was not a patent print,” Hannah said.
“Right,” Miss Hodges confirmed. “A latent print is similar to a patent print, but it isn’t visible to the naked eye.”
“So this shoe print wasn’t a latent print, either,” Ben said.
“You know, I’ve never understood why people say ‘the naked eye,’” Corey said. “Aren’t eyes always naked? You never see them wearing little shirts or hats.”
Miss Hodges laughed. “That’s a good point, Corey. Maybe from now on, instead of ‘the naked eye,’ I’ll say ‘the unaided eye.’”
“So our shoe print must be a plastic print,” Ben said, looking at the three kinds of shoe prints their faculty advisor had listed on the board.
“That’s exactly right, Ben,” Miss Hodges said. “A plastic print is a three-dimensional print left in something soft, like mud or snow.”
She showed the members of Club CSI how to examine a plaster cast of a shoe print for wear patterns. Since everyone walks in their own way, everyone wears down the soles of their shoes in a slightly different way.
“What kind of shoe do you think made this print?” Hannah asked.
“Yeah, and what size was it?” Corey added.
Miss Hodges shrugged. “I don’t know. To find out, you’d have to ask a shoe expert.”
“Do you know one?” Ben asked.
She shook her head. “I’m afraid I don’t.”
Corey remembered something. “My mom has a friend who runs her own shoe repair shop. Maybe we should ask her!”
Chapter 9
After school Corey led the way to the shoe repair shop his mother’s friend owned. As they opened the front door, an electronic bell rang.
A smiling woman with black hair came out from the back of the small shop. “May I help you?” she asked. Then she spotted Corey. “Hi! How are you, Corey? How’s your mom?”
“She’s great, Mrs. Corelli. How are you?”
“I’m just fine, thank you.”
“These are my friends, Hannah and Ben,” Corey said, gesturing toward the other members of Club CSI “We’re in a club that investigates . . . things.” He thought it might make Mrs. Corelli nervous if he said they were investigating a crime.
“Nice to meet you,” Mrs. Corelli said, shaking their hands.
“We were hoping you could help us, since you’re a shoe expert,” Ben said.
She laughed. “Well, I don’t know if I’m an expert on shoes. I guess I’m an expert at fixing them.”
Hannah pulled the bag holding the plaster cast out of her backpack. “We thought maybe you could help us with this.” She took the cast out of the bag and
offered it to Mrs. Corelli.
Looking curious, she took the cast and examined it. “Is this a plaster cast of a shoe print?”
“Exactly,” Corey said. “We were wondering what size of shoe made this print.”
“Let’s see,” Mrs. Corelli said, reaching for a measuring tape. “The extra plaster around the print means I can’t use the Brannock Device.”
“What’s a Brannock?” Ben asked.
Mrs. Corelli held up a metal measuring device. Ben had seen them at shoe stores. In fact, he’d put his foot in one more than once. “One of these,” she said. “The kind shoe salesmen use to figure out what size shoe you wear.”
“I’ve seen those lots of times,” Ben said. “I just never knew they were called a Brannock.”
“Named after Charles Brannock, who invented them back in the nineteen twenties. He actually made the prototype with an Erector set.”
“What’s an Erector set?” Corey asked.
Mrs. Corelli laughed. “A kind of construction toy you’re way too young to have heard of.”
She used the tape measure to see how wide and long the shoe print was. She wrote down the measurements and then consulted a small chart pinned to the wall. “Ten D,” she said. “That’s a very common size in men’s shoes.”
This was disappointing news. If the shoe print had been in an unusual size, it might have helped point the way to a suspect.
“At least that proves the shoe print wasn’t made by my father,” Hannah said. “I checked, and he wears an eight and a half B.”
“What kind of shoe made that print?” Corey asked.
Mrs. Corelli examined the plaster cast closely. “Well, it wasn’t a gym shoe. Or a dress shoe. Probably more of an everyday work shoe. Maybe the kind someone would wear who’s on his feet all day.”
“Does the wear pattern tell you anything?” Ben asked, remembering the term Miss Hodges had used.
Mrs. Corelli raised her eyebrows, impressed. “The wear pattern? The shoe does look worn. It’s not brand-new. But it’s not completely worn away, either. It might be a year or two old, I’d guess. On this foot, the right foot, the owner puts his weight on the inside of his foot. And he puts his weight forward, toward the ball of his foot, not back toward the heel.”
