Five Days Post Mortem

by L. T. Vargus

  “I hope you like Korean tacos,” Fowles said.

  “Never had ‘em. But I like Korean food, and I like tacos, so I don’t see how we could possibly go wrong here.”

  The half-smile seemed to constantly play at the corners of the entomologist’s mouth, but now the crinkles at the corners of his eyes deepened. Darger decided she might as well take the opportunity to do a little digging about her potential employer.

  “So how long have you been with Prescott Consulting, Dr. Fowles?”

  “It’s not doctor, actually. Not yet, anyway. I won’t defend my dissertation until next spring.”

  “What’s your thesis?”

  “Well, I won't give you the full official thesis title, because it's nearly a paragraph all by itself, but the subject is the effect of environmental factors on arthropod succession in human remains. I’ve just completed the largest forensic entomological decomposition study with real human cadavers. It’s more common to use pigs, but thanks to Dr. Prescott, I received a special grant that allowed me to conduct the study at a body farm. And to answer your initial question, I’ve been with the firm for three years.”

  She’d noted that he’d now referred to their boss by both her Christian name and her official title. Interesting. Familiar on the one hand, professional on the other.

  “And you like the work?”

  “Absolutely. I probably don’t have to tell you that there’s not an incredibly high demand for full-time forensic entomologists in most bodies of law enforcement. It’s much more common to have a faculty position at a university and only be called upon from time-to-time to aid in an investigation. Working for Dr. Prescott is a unique opportunity for someone like me.”

  Darger nodded, secretly disappointed that it didn’t seem that she’d be getting any dirt on Margaret Prescott. She should have known. Fowles struck her as too professional — and perhaps too kind — to badmouth their boss.

  “Are you the only Bug Guy, then? Or does Prescott Consulting have a whole slew of your kind?”

  The roguish half-smile returned in full force.

  “So you’re really going to keep going with the ‘Bug Guy’ thing?” He shook his head. “I knew you were an entomophobe.”

  “I’m not afraid of bugs,” Darger said. When Fowles raised an eyebrow, she added, “Not any more than your average normal person.”

  “I am the sole entomologist on staff, though there are other analysts with different specialties. Antonio Miles runs all the polygraphs. Felicia Barrett is our handwriting expert. Dr. Granholm spent 40 years as a top forensic pathologist before joining Prescott Consulting. There are others, but we tend to work solo.”

  The line for the food truck had moved at a steady pace since they’d arrived. Fowles and Darger were at bat.

  Darger couldn’t decide between the chicken, shrimp, or beef bulgogi tacos, so she got the three-way combo that came with one of each. They came in a paper food boat, topped with kimchi slaw, sesame mayo, and cilantro.

  She and Fowles stood side-by-side on the sidewalk while they ate, feet spread apart to save their shoes from being splattered with the juice that sluiced down through their fingers. It was sloppy eating, and an errant droplet of sauce found its way onto Darger’s sleeve. She glanced over at Fowles, noting that his clothing remained immaculate. Of course.

  She dabbed at the splotch with a napkin and refocused on her remaining tacos. They were savory and sweet, creamy and tangy, crunchy and chewy all at the same time. And then a little pungency from the kimchi. In short, delicious.

  Fowles paused in between tacos, watching to see how she was enjoying the food.

  “I almost took you to the bougie Peruvian place down the street. And the food there is excellent — don’t get me wrong — but something told me this was more your style.”

  Darger licked a piece of cilantro off her knuckle and shook her head with satisfaction.

  “You weren’t wrong.”

  Yeah, maybe he wasn’t so bad after all. Darger liked that he’d opted for the food truck over trying to impress her with something extravagant or expensive.

  Fowles wiped his hands with a brown paper napkin, then wadded it up with his food tray and threw the whole mess in a nearby garbage can. Darger finished her last bite and did the same.

  “So what will you do next?”

  “I was thinking I’d go talk to Shannon Mead’s family. Maybe look over her house, try to get a feel for who she was. Right now it doesn’t look like the three victims have much in common, aside from being female. If I dig deeper, though, maybe I’ll find some connection.”

  When she looked at him again, the pervasive smile had faded.

  “I noticed that. From the files, I mean. How different they seemed from one another.”

  Darger thought he was probably flicking through the crime scene photos in his mind, recalling each grisly tableau.

  She did the same, calling them up in order.

  Holly Green was the first. A student at Sandy High, fifteen years old. She was on the volleyball team. Popular. Outgoing. A loud and friendly personality by all accounts. She’d gone missing after a volleyball tournament. Five days later, her body was found in a creek on the rural northern edge of Sandy. A Boy Scout troop spotted her lodged under a concrete bridge. A dark thing bobbing in the water. Swollen to a blimp-like shape.

  A 43-year-old accountant named Maribeth Holtz was the next victim, found washed up near a local reservoir. Married with two college-aged sons, both out of state. She and her husband, a mechanical engineer, lived a quiet life. Almost hermit-like, without many social contacts in the community. Initially, this led the police to suspect Maribeth’s husband for both murders. But Mr. Holtz had a solid alibi for both disappearances — he was on a business trip, at an engineering conference at Georgia Tech where he even appeared on a panel that was streamed live on the internet within the window of time the medical examiner’s report suggested the murder took place.

  And finally Shannon Mead. 28. Single. Only in her second year at Litchfield Elementary School, but already popular among students and parents. Still very close with her own parents who lived a few miles away on the outskirts of Portland. She and her mother were both prominent figures in the Presbyterian church, active participants in a variety of charitable causes.

  There had to be something linking the women in a place as small as Sandy. Some way the killer knew all three or a connection to the town at the very least. Had the murders occurred in the city, she could have accepted that the victims were random. But a dot on the map like Sandy had to be chosen.

  When his Subaru came into view, Fowles pulled a set of keys from his pocket and aimed the fob at the vehicle, unlocking the doors. Darger climbed into the passenger seat.

  He started the car and then turned to look at her.

  “Would it be OK if I came along?”

  “When I talk to the family?”

  He nodded.

  “Are you sure you want to? It can be pretty… intense.”

  “If you think my tagging along would be inappropriate, I understand. But I’m a proponent of cooperative learning and reciprocal teaching. The better you understand the entomology, the better for the investigation. And vice versa.”

  Again, Darger was surprised by Fowles. Most of the science geeks she’d known over the years wanted nothing to do with the walking, talking human evidence left behind after a homicide: the grieving family members, the jittery witnesses, the shifty-eyed suspects. The geeks preferred their specimens to stay safely contained in Petri dishes and under glass slides.

  She considered the fact that he might regret his decision once they were knee-deep in the emotional quagmire of bereavement. But if he wanted the experience….

  “I have no objections to your coming along. But I need to grab some things from my car. We’ll have to drive back to the park first.”

  “Not a problem.”

  She watched Portland shrink in the rearview mirror as they headed out of th
e city and back into the countryside, and she wondered what other peculiarities Fowles might reveal.

  Chapter 6

  “It’s your turn, by the way,” Darger said.

  “My turn?” He regarded her quizzically, still watching the road out of the corner of his eye. “For what?”

  “I thought we were swapping information. All that cooperative learning stuff.”

  He turned back to face the windshield as he spoke, hands fidgeting on the steering wheel.

  “I’ve made the mistake of delving into the more graphic forensic details around mealtimes in mixed company before. I just wanted to give you ample time to digest your lunch.”

  “Very thoughtful. But I think I can handle it.”

  “OK. Do you remember the L. sericata I showed you?”

  It was a moment before Darger figured out what he was referring to.

  “You mean the maggot?”

  His persistent smile widened.

  “Yes. The maggot,” he said. “Lucilia sericata is one of the first—”

  Darger stopped him.

  “Biology was never my strongest subject. All that Latin jargon. Do me a favor and pretend you’re talking to an idiot for a minute.”

  “I don’t think you’re being fair to your intellect, but as you wish. The common green bottle fly — also known as the sheep blow fly — is one of the most typical species we find on carrion. It is also often one of the first. In my own study, we consistently observed L. — sorry, blow flies — on the cadavers within fifteen to twenty minutes.”

  “Wow. But you were outside, right? What if the corpse is indoors?”

  “That would be a study I’d love to take on sometime in the future, but as far as I know, no one has tested that specific environmental variable. There are certainly examples in the literature that suggest both blow flies and flesh flies are present within hours, even in a closed room. I’d guess that certain factors — whether or not there was a window left open, for example — would affect just how quickly the insects arrive. But these are remarkable scavengers. Perhaps the most efficient in the world.”

  Darger suppressed a shudder. She didn’t want Fowles thinking she was some kind of wuss.

  “Flesh flies?”

  “Sarcophagidae. Another major player. You see, the particular conditions of the body, the environment, the time of year, ambient temperature and humidity, etc… all of these variables have an effect on what forensically-relevant arthropods are in abundance as well as what life stage they’re in.”

  “Forensically-relevant arthropods. Thanks for dumbing it down,” Darger said.

  Fowles rolled his eyes but smiled along with her.

  “The important bugs.”

  “Right.”

  Fowles reached behind him, into the detritus of papers and books in the back seat and drew forth a 3-ring binder.

  “Perhaps pictures would help make things more concrete for you,” he said, handing her the folder.

  Darger set it in her lap and opened the cover. Keeping his eyes on the road, Fowles pointed at the first set of photographs. One showed a cadaver in a field, surrounded by parched brown grass. Underneath that was a close-up of a fly.

  “Allow me to use our friend the green bottle fly as an example.”

  Its eyes were blood red, and the lack of pupils made them seem directionless, almost sightless. But the fly’s thorax was a lovely shade of iridescent green, bright and metallic.

  “Huh. It’s kind of pretty,” Darger muttered.

  This statement excited Fowles enough that he slapped his hand against the steering wheel.

  “Now you’re starting to see! Even the non-butterflies of the world can be beautiful in their own way.”

  Darger flipped the page, past more images of various insects — flies mostly — on the corpse. A few pages in, she was greeted by a macro shot of four flies and what looked like a pile of rice.

  “The life cycle begins here. After mating, the female flies find their host. Usually some form of carrion—”

  Closing her eyes, Darger held up a hand and interrupted.

  “Sorry. Usually carrion?”

  “Yes, well… myiasis with L. sericata is not uncommon, especially with sheep in the UK and Australia. But there are isolated human cases now and again.”

  “Do I want to know what myiasis is?”

  “It’s an infection of fly larvae in living tissue.”

  “And back to bugs being totally disgusting.”

  “They’re not all death and decay, though. Have you ever heard of maggot therapy?”

  “Now you’re just making things up.”

  “I’m not! When traditional methods fail, and under the guidance of a trained physician, sterile maggots can be applied to an infected wound. Not only do they consume the necrotic tissue and the infectious bacteria and thus clean the wound, they also release antimicrobial enzymes. It’s supposed to be quite painless.”

  Darger raised an eyebrow.

  “Just out of curiosity, where does one obtain sterile maggots?”

  “You raise them, of course.”

  “Oh, of course.”

  Fowles redirected her attention to the folder with a jerk of his head.

  “Anyway, we were discussing the life cycle of the green bottle fly. The female extends her ovipositor—”

  Darger fixed him with a dubious look.

  “Sorry. Her… egg tube. The eggs are deposited, as many as two or three hundred at a time, on the host.”

  “So those little clumps of rice are eggs?”

  “Precisely. At 70 degrees, the eggs will hatch in approximately 21 hours.”

  He indicated Darger should turn the page. She did.

  It was a full-color spread of maggots. They were small, yellowish, and plump, feeding off the red-pink flesh in masses.

  “Here we have L. sericata in the first instar stage. Which is really just a fancy way of saying larval stage. This species will progress through three instar stages, each with a specific duration. Sticking with our example of 70 degrees, over the course of four to five days, they will grow from 2 mm to 20 mm. The larvae are essentially feeding machines, eating non-stop for those five days. The spiracles on the rear end allow it to breathe while it eats.”

  “Handy,” Darger commented before Fowles continued his lecture.

  “So the first instars migrate into the body, excreting special digestive enzymes that speed up the putrefaction process. They like both their temporary home and their meals to be wet and soupy, you see. But don't let that fool you. Their mouths are equipped with a set of teeth-like hooks which they use to scrape and shred the decaying flesh.”

  Darger’s vision blurred. She’d always felt she had a strong stomach, but this was beginning to make her queasy.

  She snapped the folder shut.

  “I did warn you,” he said. “About my sharing directly after a meal.”

  “It’s not the pictures. I mean, it is, but it’s because we’re in a moving car. I get motion sickness from reading in the car and…”

  “Looking at pictures of maggots eating human flesh?”

  She laughed and rubbed at her brow.

  “Yeah.”

  “Then here’s the abridged version. Earlier I gave you a time frame for the life cycle at 70 degrees. But when the ambient temperature rises, things really start to get exciting. The life cycle is accelerated. At 80 degrees, for example, the time it takes for the eggs to hatch goes from 21 hours to 18.”

  “And the same goes for the larval… I mean, instar stages?”

  “Yes! Exactly. At 80 degrees, they would cycle through the first, second, and third instar stages and on into the prepupal stage in only three days. That’s why knowing the ambient temperature and other environmental factors is so crucial for estimating the postmortem interval.”

  Pushing the stomach-churning images from her mind, Darger tried to focus on what Fowles was telling her.

  “So you take samples from the body, figure o
ut what stage they’re at and then count backward to figure out when the person died. Is that right?”

  “Correct.”

  “What kind of effect does being in water have on the life cycle of the flies?”

  His eyes practically lit up with what Darger could only describe as childlike delight.

  “Now that’s the kind of question that leaves no doubt in my mind that you would have made an excellent biologist. Forget your trouble with Latin. You have the innate curiosity and stubborn tenacity of a born scientist.”

  Cocking her head to one side, Darger raised an eyebrow.

  “Are you flirting with me?”

  Fowles chuckled.

  “It’s just that you’ve gotten right to the heart of the problem. Now keep in mind that the only studies I know of were conducted with pig carcasses. There’s anecdotal literature on arthropod succession on submerged human remains but no official studies. I’d love to get another grant and use the body farm to do one myself, but I’m getting off-track again.”

  He put a hand to his head, and the gesture reminded Darger of an absent-minded old man.

  “Being submerged in water drastically changed the blow fly colonization on the pig carcasses.”

  “How so?”

  “The entire life cycle was delayed five days.”

  “Huh. That matches up with the time of death for our victims. Does that mean you didn’t find any blow fly activity on them?”

  “Not exactly.”

  He swallowed, his face growing more serious.

  “The larvae I found in Maribeth Holtz were second instar.”

  Even as a newbie to the world of forensic entomology, Darger knew that didn’t make sense. She tapped a finger against her cheek, pondering it.

  “OK. Maribeth was found in shallower water. Maybe she’d washed up on shore for a while. And the temperature could have expedited things. Was there a heat wave that week?”

  “That’s what I initially considered, but it wasn’t nearly warm enough to explain that kind of acceleration to the life cycle. And then they found Shannon Mead.”

  “And she was the same?”

  “I found first instar on Shannon. Not as far along as Maribeth Holtz, but still much further advanced than if she’d been in the water for five days.”