Sergeant Cage arrived at the scene 20 minutes later. Cage opened the trunk to take out the detection kit and pulled out a pair of gloves from his pocket, walking into the room while listening to Jimmy explain the process.

The first things Cage checked were the doors and windows for signs of forced entry, then he observed the surrounding area for footprints. It was clear that Jimmy had entered once and no one else had entered the house afterward, so the footprints were very important. The door was kicked open by Jimmy, showing two footprints matching Jimmy's shoes, which did not need to be recorded.

At the doorway, Cage found half a shoeprint that only included the sole part and was very faint, clearly the visitor had cleaned their shoes outside, leaving only a slight dust trace. He placed a ruler beside it to take a photograph, then circled it with a marker.

Cage continued to circle the house to check if there were any other exits and any traces on the windows to determine whether the suspect had entered and exited from different locations.

He continued his inspection from the front door inward, discovering several footprints that Jimmy had left while entering the house, but found no more footprints beyond that point.

Cage examined the shoe rack in the vestibule, found no similar sports shoes, and essentially confirmed that the footprints at the door did not belong to the victim.

Upstairs, Cage examined the head wounds on the body and the bullet holes in the wall, then pulled out a tape measure to measure the width of the bullet holes, took photographs of them, and carefully extracted the fragmented bullets from the wall with tweezers to place in an evidence bag.

"Jimmy, go see if Dr. Kevin has arrived yet," he said.

Jimmy went outside where Coroner Dr. Kevin Smith and his assistant were already waiting. Jimmy shook hands with Dr. Kevin, then directed him upstairs for examination.

Dr. Kevin conducted a preliminary examination, then called the paramedics to take the body away.

Cage had Jimmy raise his hand to simulate the victim's headshot position, aligning it with the bullet hole on the wall. Cage then walked to the doorway, stretching out his hand to simulate the scene of the shooting starting from the entrance.

This step was clearly based on experience, as a normal ballistic calculation would require measuring the bullet holes and using either laser lighting or a hand-held line to pinpoint the shooter's position and the height of the gun.

Cage determined the shooter's position and the height of the gun, signaled Jimmy to lower his hand, then turned to the door, and sprayed fingerprint revealing agent on the doorknob. The fingerprints were very dense and intermingled, somewhat blurred, but there were still a few relatively complete ones, which Cage collected and placed in an evidence bag.

He checked a few other rooms as well, which were relatively intact and not messily ransacked, indicating that this crime was a deliberate murder.

Cage then took Jimmy out of the house, looked around, and said to Jimmy, "Jimmy, go around and ask if any of the neighbors heard gunshots or saw any suspicious people, and also see who might have surveillance cameras installed. Check it out."

"Okay," Jimmy went to the neighbors, knocking door to door, and a few did not answer, but that didn't matter much, as none of the neighbors had heard gunshots, nor had they noticed any suspicious individuals near their homes.

"Cage, there's a problem; no one heard the shots. It must have been a silencer. If it had been normal gunfire, someone would have heard it. Also, there are no surveillance cameras around, making it hard to gather information," he reported.

"Hmm, let's head back then, and see if the traffic camera footage shows anything. Also, enter these fingerprints into the fingerprint database for comparison," he suggested.

"Traffic cameras are unlikely to locate the suspect. I know this area; all the nearby intersections are small and not equipped with cameras," Jimmy responded.

Cage and Jimmy did not patrol further but instead returned directly to the police station, where they scanned the extracted fingerprints into the computer and submitted them to the fingerprint database, waiting for the results.

The coroner's office called to report that the autopsy was complete. Cage went to pick up the autopsy report while Jimmy waited at the computer for the matching results.

When the results came out, Jimmy looked at the printed report, which showed no matches; they had collected three fingerprints, and none had matched.

These fingerprints were in a criminal fingerprint database where all arrested criminals are expected to leave their fingerprint records. If there were no results from this database, there would be basically no way to identify them, unless they committed a crime again and their fingerprints were recorded, potentially leading back to this case.

Cage returned with the autopsy report and also picked up the bullet report from the lab.

"Jimmy, the reports are in, write an incident report and submit it. The victim had no next of kin on record, the cause of death was a gunshot to the head, the bullet was a 9 mm Parabellum from an unknown handgun model.

The following are the suspected characteristics of the perpetrator: based on the wound and the single bullet hole in the wall, it is essentially determined that the height of the shooter is about 180 cm. The shoeprint possibly belongs to some brand of sports shoes, the gender of the perpetrator is indeterminate, neighbors heard no gunshot sounds, likely because a silencer was used. Based on the bullet and the sales figures for common handguns, it is likely that the handgun was a Beretta 92F with a silencer."

"Okay," Jimmy took the report and started on the incident report, which he usually tried to minimize and simplify as much as he could. However, with a case involving a death, it was troublesome—he now had to deal with the crime scene investigation, case evidence, autopsy report, bullet report, suspect characteristics, etc. After getting everything sorted out, there was no need for patrolling today; he could just clock out directly.

Jimmy finished the report by nightfall, placed it on Cage's desk, and went to change out of his uniform, ready to head home.

Jimmy's police car had become a shared vehicle at the station. Whoever was going on night patrol would choose to drive it to test the patrol lights at night.

It seemed like Cage and Jimmy had done almost nothing, merely recorded some details and put the case on hold. The main issue was that they did not have enough resources to focus on such unresolved cases. Every year in the United States, there are countless such cases, and every police station has cases that remain unsolved for years, even decades.

If this case later appeared to be linked to other cases, it could be combined with other cases for joint investigation and handled then.

You might think they are being frivolous, nothing like the tenacious police officers in movies and TV shows, but that's reality. In the United States, the overall homicide case clearance rate is just over 50%. In recent years, there have been roughly 16,000 to 20,000 homicides each year, leading to many unresolved cases nationwide. By the way, the homicide case clearance rate in China has consistently been over 99% in recent years, according to data published by the Ministry of Public Security.

For American police, if no one reports a crime or no body is found, it is as if there was no homicide, at most it's treated as a general shooting incident with a report filed and closed.