When a criminal investigation in Japan stalls, police often turn to a technique called “miatari,” regarded as a bastion of last resort.

It requires an officer to have committed hundreds of mugshots to memory, just in case a criminal suspect is spotted in the street or some other public place.

One officer stands out in this regard, and he, like his fellow colleagues, is attached to the Criminal Investigation Liaison Division of Tokyo’s Metropolitan Police Department.

The man is in his 40s and his specialty is spotting suspects in busy train stations. He continues to deliver results year after year when all other methods--surveillance cameras and routine questioning--have failed.

The MPD has taken around 1,300 suspects into custody using this method over the past 20-odd years.

The officer, who has the rank of police inspector, has detained more suspects through miatari than any other of his colleagues in active service. He agreed to be tailed by an Asahi Shimbun reporter while on his beat.

It was a humid day in mid-September, and the man wearing a T-shirt, chino pants and sneakers took up position at a gateway to a major rail hub in Tokyo used by more than 100,000 passengers a day.

He wiped away sweat as he stared intently at passers-by, most of whom were looking downward because they were preoccupied with smartphones in their hands.

The man always carries mugshot flashcards of around 500 criminal suspects, which he thumbs through whenever he has a spare moment. Doing so repeatedly, at least dozens of times a day, allows him to readily recall the facial features, physiques and names of individual suspects.

When the inspector is on the prowl, he concentrates on the eyes, nose, mouth and ears of pedestrians as well as moles, if any, and other distinguishing features. Doing so has enabled him to spot individuals who appear strikingly like images of suspects he has memorized from mugshots.

Surveillance cameras often form an integral part of any police investigation these days despite the fact footage generally only ever captures movement in one direction. Miatari investigators, by contrast, look at their targets from various angles.

“It is something that only humans can do,” the inspector said.

The man said he becomes so absorbed in his work that his concentration runs out after two hours on his feet at a train station. At times like that, when his attention wanders, he tries to conjure up images of past arrests.

“Wanted criminals could turn up at any moment,” he tells himself.

The inspector spent six hours that day keeping an eagle eye out for suspects, except when he had to use a restroom, but to no avail.

He has been trying to perfect the miatari search method for around 10 years.

RUNNING ON EMPTY

To date, he has arrested around 100 suspects using this method, more than any other MPD investigator in active service. That works out to an average of around 10 suspects a year, but most days he comes up empty-handed.

When his efforts fail to pay off for days on end, the officer said he likes to don the shoes he was wearing when he arrested a suspect.

“You will be able to catch one today if you are in this pair of shoes,” he tells himself to lift his spirits.

“Although it’s make-believe, it’s fine if it cheers me up,” the man said.

The inspector decided to become a miatari investigator after taking a course on the technique when he was serving as an officer at a police station. He encountered an investigator who had committed hundreds of faces to memory.

“It’s like artisanship,” he said he thought at the time. “That’s so cool.”

He applied for the job of miatari investigator and got a corresponding assignment in 2008.

On the 10th day in his new post, the officer had an opportunity to visit a busy commercial district of Tokyo in the company of his superior. “Oh, that’s him,” he thought when he walked past a man of slight build.

He went around the man again and checked his eyes, nose and mouth. The features coincided with his mental image of the suspect, except the man should have been taller.

The officer felt slightly unsure, but his superior double-checked the man’s face from the police file and gave the green light. Several investigators approached the man and arrested him. It turned out he was a suspect in a drug case and had been on the run for about six years. The officer’s eyes proved more reliable than the official record.

He went on to track down a foreigner in breach of the immigration control law in a busy commercial district in 2015. He learned later the man was also wanted in his home country for suspected murder.

The inspector said he bears in mind that he should get rid himself of preconceptions and foregone conclusions while he is on duty.

“What I am doing is essential as a bastion of last resort,” he said. “I will continue to serve steadily in this job until I retire.”

The miatari technique, first adopted by the Osaka prefectural police in 1978, was introduced by the MPD in 2001.

The MPD’s miatari investigators, who are affiliated with the Criminal Investigation Liaison Division, each commit around 500 faces to memory.

The MPD refuses to divulge the number of miatari investigators on its books but says it has basically quintupled from the time the method was first introduced, because the technique delivers results.