The Forensic Doctor Better Than a Detective

”At that time, this conclusion seemed quite complete.”

Jiang An nodded thoughtfully, his gaze still fixed on the neck wounds: ”Of course, I completely agree with the judgment of the cause of death.”

”The conclusion of mechanical asphyxiation is indeed unquestionable. However,”

he changed his tone, his voice becoming more solemn, ”I am now more concerned with another key issue—did the perpetrator use their left hand or right hand when committing the crime?”

Upon hearing this unexpected question, an unconcealable trace of surprise flashed across Mr. Qin’s face.

In his many years of case-solving experience, previous forensic examination reports were already detailed enough, and the determination of the cause of death was quite clear. He had never thought that further speculation on the perpetrator’s hand habits was necessary on this basis.

Jiang An seemed to see through his doubts, slowly extending his left hand, gesturing a compression motion mid-air.

”Look, if we carefully analyze the distribution pattern of these wounds, we will discover a very interesting detail—the dense thumbprint marks on the left side of the neck correspond exactly to the pressure point of the perpetrator’s left thumb.”

”And the relatively sparse marks on the right side match the distribution characteristics of the other four fingers of the left hand.”

”This peculiar distribution of traces strongly suggests that the perpetrator is likely to be left-handed, commonly referred to as a lefty.”

As soon as Jiang finished speaking, Mr. Qin leaned forward thoughtfully, his gaze focused on Jiang An, his tone cautious and curious: ”Mr. Jiang, I am an outsider and not very familiar with trace identification, but listening to your analysis just now, I have had a question in my mind.”

”If the perpetrator is truly left-handed, then according to conventional inference, there should be only one thumb mark left on the left side of the neck of the deceased.”

”But look at the clear display in the scene photos and reports—the marks on the left side are intricate and complex, clearly more than one.”

”Initially, the forensic experts in our department thoroughly examined the scene and concluded that the perpetrator likely applied force with both hands simultaneously, pressing down the neck, which led to the asphyxiation of the deceased.”

Upon hearing this, Jiang An responded with a light ”Hmm,” ”Mr. Qin, what you pointed out is very critical.”

”Why don’t we take a closer look at this image—you see, there are indeed only four relatively concentrated marks on the right side of the neck, and they are arranged rather orderly.”

”But what about the left side? Counting carefully, there are exactly three.”

”You mentioned finger slip just now; this is indeed a common phenomenon in forensic identification, but if we strictly adhere to the ’left hand alone’ model for deducing: when the perpetrator strangles with the left hand, there should only be one thumb impression on the left side, while the right side should correspond to the remainder of the fingers’ pads and nails traces.”

”But now the number of traces doesn’t match at all—six on the left side, three on the right side, how should this be explained?”

Upon reaching this point, Jiang An paused slightly and continued: ”Mr. Qin, let’s return to the most basic physiological structure—a human hand has five fingers.”

”When the perpetrator applies pressure with the left hand, ideally, there should appear a thumb print on the left side and four fingers arranged side by side on the right side.”

”But we must consider a key variable: the deceased wasn’t motionless during the attack but struggled, twisted, and may have even fiercely resisted.”

”In such a dynamic process, the perpetrator’s fingers may have slipped, shifted, or even repeatedly re-exerted force.”

He picked up a magnifying glass, urging everyone to closely observe the close-up of the left-side trace shape: ”I insist on the conclusion of ’left-hand operation with finger sliding’ mainly because of the significant morphological differences among the three finger pressure marks on the left side—some are deep, some are shallow, some have blurred edges, and some carry clear nail edge indentations.”