Chapter 148: The Footprint Expert

Case Processing Center.

The greenery leaves along the corridor were blackened, like neglected old houseplants.

Several veteran detectives imparted advice to Jiang Yuan.

In the interrogation room, what to say and what not to say.

In the interrogation room, suspect Liu Chang had just finished reading the "Notification of Rights and Obligations for Criminal Suspects" and was signing it.

In homicide cases, even the county public security bureau proceeds step by step, strictly following the textbook.

Otherwise, plenty of people will be eager to teach you how to do your job.

"What's your name?"

"Liu Chang."

"Have you ever used any other names or nicknames?"

"No." Remember the website

"Your ethnicity and date of birth?"

……

"I want to see the footprint expert," Liu Chang answered a few questions, then suddenly refused to cooperate, shouting.

His expression was slightly panicked, his face pale; he wore half-rimmed glasses, but honestly, he was still a quite good-looking young man.

He was also tall—quite an advantage.

Wu Junhao, sitting across from him in uniform, looked especially muscular and strong, and patiently soothed him:

"Didn't we agree? We'll finish the statement first, and the person will arrive soon."

"It's been this long—they should've arrived by now. If they can't come, just tell me straight, don't lie to me," Liu Chang's expression turned extremely serious.

His pupils kept shifting.

Wu Junhao, fierce when arresting suspects, was gentle during interrogations, still urging: "There's no point lying to you. You want to see someone? They have to be notified first, then come over, and besides, entering to meet you…"

"You said fifteen minutes ago."

"It hasn't arrived yet."

"Then show me the time."

Wu Junhao froze again—he couldn't show him the time; that violated basic interrogation rules.

"Then I want to see my dad," Liu Chang made a new demand, causing everyone inside and outside the interrogation room to change expression.

Twenty-five-year-olds are still fairly easy to fool.

People brought into interrogation rooms come up with all sorts of bizarre ideas.

Many imagine their crimes are minor or believe themselves innocent.

Liu Chang firmly believed he had killed by accident.

Only then did they have a basis for conversation.

In a real interrogation room, there's always at least one fool. That's the so-called interrogation room principle.

Liu Chang's mind suddenly seemed to snap back—this was the most tense moment.

If he refused to confess, the investigation would become difficult.

The next one or two weeks of happiness for hundreds of officers and police depended entirely on Liu Chang's attitude right now.

As for Liu Chang's father, he was a fifty-year-old veteran of the political arena, holding a certain official rank—"troublesome" was too mild a word.

"You're twenty-five now—you don't need parental accompaniment," Wu Junhao suddenly said, piercing Liu Chang's sensitive nerve.

He'd seen too many teenagers trying to prove their manhood through words and shouting.

A slight poke at the "troubles of growing up" muscle, and they'd explode on the spot.

Liu Chang indeed grew furious, his hands trembling, shouting: "I want to see the footprint expert—hurry up!"

He no longer shouted for his father.

Wu Junhao exhaled in relief but dared not continue the interrogation.

Liu Chang's father was actually being interrogated right next door.

Liu Chang's father was far more experienced.

He clearly looked like a minor official—when they arrested him, he'd spoken in bureaucratic tones, somewhat stern.

Such people usually possess iron wills, like manure in a sun-baked pile of rocks: smooth and slippery on the surface, seemingly hard, but hollow inside when cracked open.

But for Old Wu, he wasn't worried about interrogating Liu Chang's father.

For people like him, the simplest method is slow, steady pressure—soak even the hardest manure in water for days, stir it slightly by hand, and it dissolves.

Old hands who once held power and money decay quickly and have many weaknesses.

It's the young like Liu Chang who are volatile, unstable, and prone to retracting confessions.

Just moments ago in the car, he'd confessed everything in detail; now, inside the interrogation room, he's changed again—who knows what strange behavior he'll show next?

People who've killed someone have, to some degree, psychological issues.

Wu Junhao didn't want a crystal-clear murder case to turn into a messy, snot-like mess.

Outside the interrogation room.

The professionals realized Liu Chang's emotions were uncontrollable; after quickly briefing Jiang Yuan, they let him enter.

A group stared intently at the surveillance monitors, fists clenched, as serious as fans of the home team.

Jiang Yuan knocked and entered the interrogation room.

Wu Junhao used the largest interrogation room—long and wide, with iron bars blocking off the third near the door.

Liu Chang sat inside, unable to find a single window; the overhead spotlight made him even more agitated.

The so-called "tiger bench" was stretched to its maximum.

A man 1. 3 meters tall had pulled the bench to its highest setting—his legs spilled over the edges, his arms on the table extended beyond, making it nearly impossible to lock the handcuffs.

The two restraint straps behind were fine, but Wu Junhao hadn't put them on him.

Those things were uncomfortable—far more unpleasant than a seatbelt—and he feared Liu Chang, who had surrendered, would be unhappy.

Before a suspect confesses, police always act like caring older brothers.

Only once they're fully in their grasp do the officers reveal their ruthless side.

Mature police officers are usually like mature jerks.

Immature police officers are usually like immature jerks.

Jiang Yuan was also very tall; the moment he entered, under the bright light, he almost looked like he was seeing himself sitting inside…

Liu Chang was much the same—in a flash, he almost saw another version of himself walking in.

Both seemed momentarily stunned, facing each other.

Liu Chang, from a small town, was a genuine minor official's son, raised in comfort.

"This is our footprint expert, Dr. Jiang," Wu Junhao gestured for Jiang Yuan to sit beside him, then introduced him to Liu Chang.

"How old are you?" Liu Chang's pupils shrank slightly, but he asked first.

Jiang Yuan, seeing such a young suspect—even though he'd read the case file, heard about him on the way, and seen him outside—still felt strange facing him directly.

"Twenty-four."

"Younger than me?" Liu Chang suddenly turned sharply toward Wu Junhao, his feet trembling:

"Who are you fooling? Sending a fake? Is that funny?"

Wu Junhao blinked, then slapped his thick forehead with his large hand.

"Why didn't you say so earlier? We have so many people—we could've easily faked one. Do you think experts should be forty or fifty, preferably bald or with white hair?"

Wu Junhao wiped his greasy hair and continued:

"If I'd known, I'd have just sent a bald cop. Why go all the way to get Jiang Yuan? Our team lacks everything except age and baldness."

Liu Chang was left speechless.

And he thought the big man actually made sense.

He carefully studied the young man across from him.

"How did you figure out my height? I heard the last footprint expert was a famous one from the province."

His question showed some technical knowledge—he'd clearly researched beforehand.

Jiang Yuan countered: "Why does this matter to you?"

"I just wanted to understand. I'm much taller than average; when the incident happened and I saw all the footprints, I knew something was off. Lowering my height was my own decision," Liu Chang said calmly.

Just that one sentence revealed much information.

If his words were true, first, Liu Chang didn't know what the previous fingerprint expert had judged his height to be.

In other words, his father's connections hadn't reached the level of leaking case details.

Chen Wenming had estimated 178 to 185 cm; if Liu Chang were just a bit taller, reporting 185 would've put him squarely in range—then the special task force's scrutiny of him would've been several times stronger.

Second, Liu Chang said he himself decided to lower his height, meaning someone else decided other things for him.

Most likely his parents.

In other words, this sentence proved his parents were indeed covering for him.

Finally, Liu Chang revealed his psychological state.

Young people wanting to decide their own future, wanting to challenge the world with their own understanding—nothing new.

Some end up becoming national founders—referring to Sun Yat-sen.

Others end up as murderers—referring to Qin Wuyang.

Jiang Yuan looked even more deeply at Liu Chang.

From the way he felt facing him, was this guy actually hoping to become accomplished?

Thinking that after killing someone unexpectedly, he could still walk free, and wanting to prepare for next time?

"If you won't talk, then I won't either," Liu Chang felt he had the upper hand over Jiang Yuan.

Jiang Yuan smiled and said, "Estimating height is actually a systematic process—all of it's in the books."

"I just want to hear you say it."

"Alright, the simplest point is judging height by foot length. There are some empirical rules."

Jiang Yuan spoke slowly: "For example, in ancient China, there was the saying 'seven heads tall, five seated, three seated cross-legged'—meaning an average person's height is seven times their head length, and foot length is roughly equal to head length."

"But aren't there people who are nine-heads tall?"

"Those are exceptions. Let's stick to general patterns first."

Liu Chang nodded in agreement: "Okay, so multiply by seven?"

"Shanghai people: multiply by 6. 5, Northeasterners: 6. 76, Shaanxi people: 6. 34, Chongqing: 6. 56…" Jiang Yuan gave a complete answer outright.

"But I was wearing shoes that day!" Liu Chang still resented this most.

"And the shoes were a bit smaller than normal—they squeezed my feet, so the size didn't match my usual."

"Could you tell?"

"I could tell," Jiang Yuan nodded. "Shall I continue?"

"Go on."

"To further estimate height, you need to add foot width data. Your feet are long, but wider than average—that's another detail."

Liu Chang listened as the young forensic doctor spoke at length, and surprisingly began to agree:

"Chinese feet are generally wider than Europeans', so foreign-brand shoes often pinch."

His foot width exceeded the norm—he felt it deeply, and shoes were hard to buy.

"Then there's foot sole area and metatarsal width. Adding these two data points significantly improves the regression equation's accuracy," Jiang Yuan explained carefully—all publicly available information.

According to interrogation experts, letting Liu Chang talk a bit longer at this point was beneficial.

Liu Chang frowned at the mention of regression equations: "You're still talking about averages. How do you know my height is exactly 193?"

"The actual range should be 191 to 195. I estimated 193 because it's the most probable," Jiang Yuan replied.

He added: "It's still mostly experience-based. Also, there are pressure marks, stride length…"

…Outside the interrogation room, the supervisors listened, baffled—some confused, some impressed but unable to articulate why. Watching the young forensic doctor and the young suspect converse, they truly sensed the tension of a TV drama.

Brilliant, yet indescribable.

"Can you explain in more detail?" Liu Chang pressed.

"It's your turn now," Big Muscles Wu Jun interrupted. "Let's first complete the interrogation record. You can discuss the rest later."

"Complete what?" Liu Chang leaned slightly back, but the metal chair wouldn't budge, making him frown.

"Just tell us why you killed him," Wu Junhao skipped the protocol and asked directly.

Liu Chang sneered: "Didn't I already say?"

"This is the official interrogation. If you say it now, it counts as voluntary confession…"

Liu Chang lifted his head and spoke slowly: "I was an idiot back then. I bumped into his son, we exchanged a few curses. The kid was dressed in rags…"

Recalling the scene seven years ago, Liu Chang felt a flicker of regret, shook his head, and said: "Anyway, I wanted to make up for it. That day, I happened to be heading that way, so I rode my bike to his house—and just happened to meet his father. The old man tried to attack me, so I had to fight back. I didn't mean to…"

"How did you know where his house was?"

"The kid told me himself. Said if you take the county road down, there are two giant stone lions with wings—that's their place." Liu Chang's voice faded further…