Monthly Archives: October 2019

Criminal Mischief: Episode #30: Evidence

Criminal Mischief: The Art and Science of Crime Fiction: Episode #30: Evidence







If Locard’s Exchange Principle is the cornerstone of forensic science, evidence is the heart and soul of the crime lab. Indeed, evidence is the sole reason it exists. Without evidence, what would the lab do? Evidence is used to determine if a crime has been committed, to link a suspect to a scene, to corroborate or refute an alibi or statement, to identify a perpetrator or victim, to exonerate the innocent, to induce a confession, and to direct further investigation. 

The modern crime lab attempts to identify and compare any evidence it receives and then links this evidence to a particular individual to the exclusion of all others. 

This brings up a critical concept: Evidence is used to eliminate suspects rather than to point the finger at any one person. Individualizing evidence eliminates everyone else and leaves the perpetrator standing alone. 

This isn’t a modern concept. Again, we look to Sherlock Holmes, who discusses in several of his stories his belief that good evidence and clear reasoning would eliminate all choices but one. My favorite comes from “The Adventure of the Beryl Coronet” in which he states, “It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth.” 


 Evidence may be either direct or circumstantial. Direct evidence directly establishes a fact. Examples are eyewitness statements and confessions, which are subjective by nature and, as such, are burdened with the problems that plague all subjective information. Eyewitnesses are notoriously incorrect in their identification of a suspect and their recall of events because memory and recall are affected by the witnesses’ mental and physical health and abilities, prejudices, experiences, and the emotion of the situation. What if the witness had poor vision or poor hearing, or held racial prejudices, or was highly emotional? Could his perception of who did what to whom, when, and how be distorted? Absolutely. Though most often these distortions are not intentional, they exist nonetheless. Studies of this phenomenon have shown that eyewitnesses may be wrong as much as 50 percent of the time. 

On the other hand, circumstantial evidence is more objective and is subject to the laws of probability. This leads to the curious fact that circumstantial evidence is often more reliable than direct evidence. Unlike an eyewitness account, accurate science is not altered by subjectivity. Its interpretation might be, but the result is the result. 

Circumstantial evidence is any evidence that is not direct. Blood, hair, fibers, bullets, DNA—indeed, all forensic science evidence—are circumstantial in nature. This type of evidence requires that the judge and jury infer something from the presented evidentiary fact. For example, if a fingerprint or hair found at the crime scene is matched to a suspect, the jury may infer that the print is that of the defendant and the fact that it was found at the crime scene links the defendant to the scene. Under most circumstances, this is not absolute proof, but is highly suggestive that he was involved in the crime. 


The forensic analysis of evidence items is done for two main purposes: identification and comparison. Identification is done to determine what exactly a particular item or substance is. Is this white powder heroin or crystal methamphetamine or sugar? Who manufactured the shoe that left the print at the crime scene? Are there petrochemical residues present in the debris of a suspicious fire? Is this brown carpet stain dried blood or chocolate sauce? 

Identification in such circumstances is critical since, if the powder is sugar and not heroin or the stain is indeed chocolate sauce and not blood, there might be no crime at all. Conversely, if heroin or blood is identified, either may become the crucial evidence in a criminal proceeding. Such identifications make up an important part of the work done by the crime lab. After testing, the examiner may state that the questioned substance is present, not present, or that the testing is inconclusive and the presence of the substance can be neither ruled in nor out. 

Comparisons are done to see if a suspect item or substance shares a common origin with a known one. That is, did they come from the same person, place, or object? Did this fingerprint, hair, or blood come from the suspect? Does this paint smudge found on a hit-and-run victim’s clothing match that of the suspect’s car? Does the bullet removed from a murder victim match the one test-fired from the suspect’s gun? 

For example, after comparing a crime scene fingerprint to one obtained from a suspect, the examiner may state that the two match (bad news for the suspect), do not match (may exonerate the suspect), or that the comparison was inconclusive, perhaps because the crime scene print was of poor quality. In the last case, the suspect is neither cleared nor condemned. 


Some types of evidence carry more weight than others. Hair and fibers can suggest, while DNA and fingerprints can absolutely make a connection. The difference is that some evidence shares class characteristics and others individual characteristics. 

Class characteristics are those that are not unique to a particular object, but rather serve to place the particular bit of evidence into a specific class. For ex- ample, if a victim has been shot, the determination that the bullet was from a 

.38 caliber handgun would make all .38 caliber handguns the possible murder weapon. Other calibers would not belong to this class and would be excluded from consideration. Alternatively, blood recovered from a crime scene could be found to be type B. It could have come from any of the tens of millions of people who share this blood type. If the suspect has type B blood, he remains a suspect and DNA testing will be required to conclusively match the sample to the suspect. But if he has type A blood, he is excluded.

A single piece of class evidence can rarely convict, but it can often exonerate. The above type B blood would exclude all persons with a different blood type. They belong to a different class and only those in the class of individuals with type B blood would remain in the suspect pool. However, if multiple types of class evidence are associated with one suspect, the weight of the evidence may make a strong case. A classic example is the Atlanta child murders case. 

In cases such as this, the sheer number of the pieces of class evidence makes coincidence extremely unlikely. What are the odds that someone else left behind this combination of fibers and hair? Though class evidence is not absolute proof that a suspect is connected to a particular location, and each bit of class evidence taken alone may not be strong, when a large number of matching evidence is found, the odds that the suspect was present at the crime scene becomes overwhelming. 

Individual characteristics are as close to absolute proof of the origin of the evidence item as is possible. The most individualizing types of evidence are finger- prints and DNA, since no two people possess either the same prints or the same DNA (the exception being identical twins who have the same DNA but different fingerprints). 

Impression evidence, such as bullet ballistic markings, shoe and tire tracks, and tool marks, may be unique enough to be considered individual evidence. Also, fracture or tear patterns, such as in broken glass, torn paper, or matches ripped from a matchbook, may possess edges that fit perfectly together like a jigsaw puzzle, thus indicating the pieces shared a common source. 

The overriding principle in the analysis of individual characteristics is that no two things are exactly alike. No two guns mark a bullet the same way. No two pieces of glass fracture in the same manner. No two pairs of shoes or sets of car tires wear in exactly the same way. 

The goal of the criminalist is to identify individualizing characteristics, for these truly “make the case” by positively identifying the source of the questioned evidence. If ballistics matched the markings on a .38 caliber bullet to those from a bullet test-fired by a suspect weapon, these markings are individual evidence. They separate this particular gun from all other .38 caliber weapons and indicate that this particular .38 was the murder weapon. Similarly, in the earlier type B blood example we just discussed, DNA could be used to eliminate all of the people with type B blood except for the one person who actually left the blood at the crime scene.

The bottom line is that class evidence can considerably narrow the field of suspects and individual evidence can narrow it further, perhaps to a single person. 


Whether the evidence is class or individual in quality, it may be used to reconstruct the events of the crime or to associate a suspect with the crime scene. 

Reconstructive evidence is any evidence that helps in reconstructing the crime scene. Broken glass or pried doors and windows may reveal the perpetrator’s points of entry and exit. Was the window broken from the inside or the outside? Did the perpetrator use a key or a screwdriver to gain entry? Shoe prints, blood spatters, and the trajectory of bullets may show where in the room everyone was and exactly how and in what sequence the crime occurred. Was the victim attacked from the front or from behind? Was the murder quick or did a struggle occur? Was the prime suspect at the scene at the time of the murder or did he, as he says, stumble into the scene later? 

Reconstructive evidence helps the ME determine who did what, where, when, and how, as well as helps determine who is being truthful and who might be lying. Crime scene reconstruction is discussed in greater detail later in the chapter. 

Associative evidence is evidence that ties the suspect to the crime scene. Fingerprints, shoe prints, hair, fibers, blood and other body fluids, knives, bullets, guns, and paint, among others, may be used to link the suspect to the scene, or prove that the fingerprints, hair, or blood is not his and that someone else must have committed the crime.

This linkage was discussed in Chapter One, but is worth a brief mention here. Evidence is supposed to link a suspect to a person, place, or object. The finding of a victim’s hair or fibers from the victim’s clothing on the clothing of the suspect suggests that they had some degree of contact, and thus links the two together. A suspect’s fingerprint, blood, or semen at the scene of a robbery, murder, or rape strongly links him to the crime scene. A murder weapon that holds a suspect’s fingerprints requires a great deal of explaining. Each of these circumstances links elements of the crime to the suspect. The link can be established through the criminalists collecting evidence and the analytical procedures of the crime lab work. When successful, the evidence may find its way into court and result in a conviction. 

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Posted by on October 22, 2019 in Uncategorized


When Your Antagonist Goes Viral

When Your Antagonist Goes Viral
by DP Lyle

Imagine this: Your protagonist is faced with a deadly enemy that can’t be seen, felt, smelled, tasted. Undetectable until it’s way too late. Imagine victims dropping all around him, many with horrible and frightening symptoms and signs. Things like blotchy purple skin rashes, raspy, wheezy breathing, bloody vomiting and diarrhea, confusion or psychotic and aggressive behaviors. Yet the cause of all this mayhem is unseen, and unknown.



How do you identify such an enemy, or defend yourself from it?

Infectious diseases have terrorized the world for centuries. The Black Death was just one, the worst, of the plagues that swept through Medieval Europe. It killed one third, maybe one half, of Europe’s population. With many of the above symptoms. The meager state of medical care—-or understanding—in 1350 could do little. The church was equally impotent. 

Imagine the terror that gripped the entirety of Europe. What caused these horrible things to happen? Was it bad air, some miasma? Was it spread by one group or another? Was it punishment for your sins?

Where could you go to avoid the plague? What could you do to protect yourself and your family? Who could you turn to? What would you do if an infected stranger appeared at your door? Would you trust your local officials or pray to a God that let this happen? 

There were no heroes available at that time.

But there have been, and are, other plagues that are more modern and equally as deadly. The 1918 flu claimed millions of lives around the world. Now we have such pleasant afflictions as HIV, Ebola, and the Marburg virus. Besides, isn’t the coming Zombie Apocalypse due to an errant virus?

Scary stuff.


Plague Doctor


The Plague was caused by a bacterium that today is easily treated with antibiotics. Drugs that weren’t available in the 14th century. Okay, great, The Black Death can’t happen today. Not so fast. What about viruses? Things like Ebola and Marburg. We have little effective testament for these guys. So, a new Black Death is always possible. And as the world turns, new creatures are evolving. A series of simple mutations could easily produce the next pandemic and yet again kill off half the population. In fact, it probably will someday. History repeats itself.

And such an unseen enemy can make for a nearly perfect fictional antagonist. I mean, you can flash a mirror, or cross, at Dracula, or fire a silver bullet into the Wolfman, or simply run from Frankenstein—he wasn’t very fleet of foot. Godzilla stomping your city to rubble creates different, but not insurmountable, problems. 

But where do you hide from a virus? 

I’ve practiced medicine for over forty years and I can say without doubt that the greatest stress placed on any human is when they face death, disease, or injury. There are so many unknowns and the feeling of helplessness is universal. The same is true if the sufferer is a parent, child, or loved one. It produces anxiety on a very basic and visceral level.

This innate fear of death and disease is part of the human experience. And excellent fodder for thriller writing. Sure Frankenstein and Godzilla are scary, but what about an unseen, unavoidable, untreatable enemy? One that has no boundaries, permeating the air you breath, the water you drink, the loved one you hug. There is nowhere to hide since the miasma can creep beneath your door.

It doesn’t bite, or maul, or stomp, or any of those physical things, but rather attacks from within. By the time the victim realizes something is wrong, it’s often too late to fix. Or worse, there is no fix.

Infectious processes have been the subject of many thrillers, both written and cinematic. Michael Crichton’s Andromeda Strain (1971) was an early example. An organism comes from outer space and kills quickly. Earthlings have no defense. Just as Europeans had no defense when the Black Death appeared. Others include The Cassandra Crossing (1976), 28 Days Later (2002), and Outbreak (1995).

Thrillers need a resilient, believable, relentless, deadly, seemingly-unstoppable antagonist. An unseen infectious creature that attacks from within fits the bill.

The Black Death:

1918 Flu:

Originally posted on the Horror Tree Blog:


Criminal Mischief: Episode #29: SKIN IN THE GAME

Criminal Mischief: Episode #29: SKIN IN THE GAME




Today, Tuesday, October 8, 2019 is the release date for the first story in my Cain/Harper thriller series: SKIN IN THE GAME.

For More Info and to Order:

Cain and Harper:

Raised as siblings by an itinerant “gypsy” family, knife expert Bobby Cain, trained by the US military in the lethal art of covert eliminations, and Harper McCoy, nurtured by the US Navy and the CIA to run black ops and wage psychological warfare, are now civilians. Of a sort. Employing the skills learned from the “family” and their training, they now fix the unfixable. Case in point: Retired General William Kessler hires the duo to track down his missing granddaughter, a Vanderbilt University co-ed. Their search leads them to a small, bucolic, lake-side town in central Tennessee and into a world of prostitution, human trafficking, and serial murder. The question then becomes: Will their considerable skills be enough for Cain and Harper to save the young woman, and themselves, from a sociopath with “home field” advantage, a hunter’s skills, and his own deeply disturbing agenda?



Cain returned home to collect Harper for the drive to Leiper’s Fork. A trip that raised ambivalent feelings. Sure it would be good to see General Kessler again. It had been many years. On the other side of the world, each with sand and grit in their hair, eyes, everywhere; Cain with fresh blood on his hands.

 But, under these circumstances? Kessler obviously adored his granddaughter. And with her parents succumbing to premature deaths, he and Miriam had essentially raised the girl. If she was truly missing, and not off on some college kid’s adventure, they would be crushed. Even a tough, old bird like Kessler.

 Cain heard the hiss of the shower coming from Harper’s room, indicating she had finished her workout. He knew she’d be ready to roll within minutes of stepping from beneath the spray. Harper wasn’t one to primp. Or waste time. 

Three years ago, a year after they had started their consulting—that nowhere near covered what they actually did—not sure there was a word for that—they had purchased the entire top floor of St. Germain Place. Before it was built out. They designed the space as a single unit with four bedrooms, an office, and a well-equipped gym that included a throwing area for Cain to remain proficient with his knives. A shooting gallery for Harper and her weapons would have been nice, but that would have violated a dozen city codes. It was all wrapped in 360- degree views of the city’s heart, the football stadium, and the Cumberland River. 

“What’s this about?” Harper asked as Cain pulled from the underground parking. 

He had called her as he left Milner’s office, telling her to get ready for a road trip. Probably just for the day but, as usual, to prep for a couple of more. You just never knew. 

“Cindy Grant. General Kessler’s granddaughter has gone missing.”

“Gone missing in a bad way?”


Cain avoided the interstate, as traffic there was unpredictable and most often snarled, instead following a more direct route. Highway 431, then 46, which melted into the one-street village of Leiper’s Fork. Calling it a village was a stretch, the “downtown” area being a couple of blocks long and the stores and restaurants sparse. Beyond, the highway resumed, becoming Old Hillsboro Road, a two-lane blacktop that wound through rolling fields and thick stands of pines and gums and oaks. A half mile south of town, General William Kessler’s estate came into view. 

“Impressive,” Harper said.

 As Milner had described, its stone construction brought to mind a medieval castle. Backed up against a hillock of dark-green pines, it possessed a commanding view of the General’s acreage, plenty of that, and the valley below. Civilian life had been good to the Kesslers. Cain knew their money had come from real estate and shrewd investing. Not to mention the various boards the General sat on. 

They were buzzed through the gate that stretched between two thick river rock columns and continued up 200 yards of winding drive that ended at a paved parking circle. A stone archway led to a pair of massive wooden entry doors. As Cain reached for the buzzer, one door swung open. 

Miriam Kessler. Thin, gray hair trimmed short, she wore black slacks and a lemon silk shirt. Cain knew she was sixty-eight but she appeared a dozen years younger. Less so today. Miriam had been at the General’s side through everything. Countless state dinners and military processions. Now she devoted her time to charities and fundraising. “Bobby Cain,” she said. “It’s been a long time.”

“How are you, Miriam?” They hugged.

“We’ve definitely been better.” 

“I don’t think you’ve met my sister, Harper.”

“I’ve heard about you though,” Miriam said, shaking Harper’s hand. “Please, come in.” Cain and Harper entered and she closed the door.

“Thank you for coming,” Miriam said. “On such short notice.”

“Anything for the General.”

“It’s been a tough week,” Miriam said. “Bill is beside himself.”

Cain remembered Miriam as always appearing fit, healthy, alive. Now, she wore a haggard, exhausted mantle. Stress lines cut into her face, her hair gray and tired. Her eyes held an irritated redness and a hint of puffiness. She looked like someone enveloped in a personal hell. Yet through that mask a glow of strength and resiliency persisted. Like so many military wives, she was a warrior. 

“Bill’s in his study.” 

She led them through a voluminous foyer and into a great room, which was exactly that. Ceilings that soared 25 feet above them, maybe more, and a massive stone fireplace, large enough to park a car inside. Plush sofas, antiques everywhere, and twenty-foot windows filling one wall. 

“Can I get you something?” she asked over her shoulder. “I’m sure Bill will want some lemonade.” 

“That would be fine,” Cain said.

 They entered the General’s equally impressive study. Kessler stood and came around his desk, hand extended, now silhouetted against cathedral windows that looked out over rolling hills of green grass and wads of thick pines. He wore gray slacks and a dark blue shirt. His hair silver, eyes deeply blue.

 “Bobby Cain,” he said. “It’s been a long time.”

“Yes, it has.”

They shook hands. Cain introduced Harper and they took seats facing Kessler who again settled into his oxblood leather chair.

“Wish it were under better circumstances,” Kessler said. “Did you have any trouble finding us?”

“None at all.”

“Good, good.”

Miriam returned with three glasses of lemonade.
“Anything else?” she asked.

“No,” Kessler said. “Thanks.” He offered her a sad smile.

“Then I’ll leave you to talk business.”

Kessler watched her go, waiting until the door closed behind her. “She’s taking this harder than me. And that’s pretty hard.”

“I imagine so,” Cain said.

“You know about loss.”

Cain stared at him.

“First being abandoned at—what was it? Two months?”

“That’s what I was told.”

“The murder of your adoptive parents. While you were overseas.” Cain nodded.

“And you, Harper. Abandoned, actually sold, by your mother.”

“You’ve done your homework,” Cain said.

 “As I’m sure you have. And will.” Kessler studied them for a beat, sighed. “The upshot is that I know each of you understand loss.”

 “From what I was told, your granddaughter is missing,” Harper said. “That doesn’t mean something has happened to her.”

 “I wish that was true.” He folded his hands before him. “But I’m a pragmatic man. Always have been.” He glanced at the door again. “I know the odds of her being alive are remote. Essentially nonexistent. It’s been a week now and she hasn’t responded. Her cell phone no longer receives calls. Something has happened. Something…unpleasant.”

 Cain wanted to reassure him but knew he really couldn’t. Mainly because the odds dictated he was correct. Still, he tried. “She’s a college kid. They do stupid things all the time. Like going away and forgetting to call.”

 “Not Cindy. Even when she was in Europe a couple of years ago, she called. Every day. Like clockwork. It’s in her nature.”

 “Do you have any evidence that something’s happened?” Harper asked.

 “Specifically? No.” Kessler shook his head. “I did call her roommate. A girl named Kelly Whitt. She said Cindy told her she was going to Colorado for a few days. She hasn’t heard from her since she left.”

 “Did she?” I asked. “Go to Colorado?”

 “She didn’t fly. Or take a train. Or rent a car, or use any of her credit cards. And her cell phone went out after about forty-eight hours. It’s last known position was in Nashville.”

 Cain was impressed, but not surprised. A retired General who had spent much of his life in intelligence, who ran dark ops in many of the most treacherous places on Earth, could get his hands on just about any information he needed.

 “Milner was a bit cryptic when we spoke. Exactly why are we here?” Cain asked.

 “Because I want you to find her. Or discover what happened to her.” He hesitated. “And make things right.”

 “I’m sure Milner told you that we don’t do missing persons.”

 Kessler leaned back in his chair, spun it slightly so he could gaze out the windows for a beat. He sighed; a deep, mournful sigh. “Let me ask you something,” He swiveled back around. “How many knives do you have on you right now?”

 “That you could find? Three or four.”

Kessler nodded. “The tools of your trade.”

Cain remained silent.

“Let me tell you a story,” Kessler said as he leaned back. “There was boy. Raised by a wandering gypsy band. Became an expert with knives. At a very early age. He put on knife throwing exhibitions all over the South. Part of the traveling show. He also became an expert second-story thief. He had many talents.” He steepled his fingers before him. “An arrest, an orphanage, and an adoption followed. Then on to the US Army. He was eighteen.” He scratched the back of one hand and then re-steepled his fingers. “His military career was destined to be bland, normal. But then his SEREs training drew some attention. If memory serves, he stayed off the radar for a week. And then suddenly appeared in his CO’s office. Something like that, anyway.” Kessler offered a half smile. “Ruffled more than a few feathers.”

 Kessler had definitely done his due diligence.

 “But our hero’s shenanigans attracted the attention of the Pentagon, a few other agencies. And his military career took a sudden turn. Ranger School, Seal and Delta training, followed by various Special Ops missions. Intelligence gathering, communication and supply disruptions, and a few targeted eliminations. Most, but not all, sanctioned.” He held Cain’s gaze a beat. “Yet, each necessary.” Kessler leaned back again, arms folded over his chest. “Then his parents were murdered. By three men. Each later met an unexpected and not so pleasant demise.”

 Again, Cain said nothing.

 “Our protagonist in this little tale then left the military. But not, for lack of a better term, special ops. Only his employers changed. Private, rather than military. His methods? Well, let’s just say the military—his gypsy family, too—trained him well.”

 Still, Cain remained silent.

 “Then, there’s another tale. Child sold to an itinerant family. By her alcoholic, half- Cherokee mother. Smart, precocious. Family disrupted when their past caught up to them. Orphanage, adoption, also military. Intelligence, PsyOps, CIA. Our heroine proved quite adept at running off-the-grid ops. The kind that could slam you in front of a Senate subcommittee.” He gave a half shrug. “Then, a chance reunion. In a hell hole.” 

Cain wasn’t really surprised that Kessler knew his background in intimate detail. They had a history. Kessler had run several of Cain’s missions. But Harper? Kessler didn’t know her. No military connection. Yet, Kessler had gone deep.

 “So, let’s get down to it,” Kessler said. “I know—I can feel it in my bones, and my bones are always right—that I will never see Cindy alive again.” Another glance toward the door. “I know that for a fact. She didn’t run off somewhere. Forget to call. This isn’t money driven. Not a ransom. This is something much worse. More final.”

 “Are you sure we’re the right people for the job?” Cain asked.

 Kessler leaned forward, his fists balled on his desk before him. “We’re soldiers. Each of us. Trained to do the tough jobs. The ones no one else will do.” He locked on Cain. “I know about Afghanistan. I know about the ones that killed your family in Tyler, Texas.” Now, his attention turned to Harper. “I know about deeply secret CIA ops. Most well below the threshold of visibility. I know much of the work you’ve done together over the past few years.” His fists relaxed. “So, yes, you’re the ones for this mission.”

 Mission? Interesting word choice. But not unexpected coming from Kessler.

Cain nodded. “What do you want us to do?”

Kessler’s blue eyes took on an extra intensity. “This is a military operation. A war, if you will. One where we, not the enemy, dictate the rules of engagement. You know me. Know I’m more of the General George S. Patton school. Stonewall Jackson, too. Never wait. Take the battle to the enemy. I want Cindy found. Dead, alive, whatever, I want her found. I want those who took her to feel the full weight of their actions. If she’s been harmed, I want those responsible harmed. If she’s been tortured, then pain and mortal fear should come their way. If she’s been murdered, I want them to suffer a similar fate.” His face darkened. “That’s what I want.” 

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Posted by on October 8, 2019 in Writing

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