Along with the increasing number of self-service stores, related crimes, including theft and vandalism, have become rampant in recent years with the majority of cases involving teenagers, a report showed Monday.

According to a report titled “A Study on Crimes at Unmanned Stores and Countermeasures,” published by the Korean Institute of Criminology and Justice, a total of 1,640 shoplifting incidents took place in Seoul from September 2020 to January 2022, which indicates that 96 cases occurred each month.

Of the total, theft accounted for 84 percent, or 1,377 cases. The use of stolen credit cards came next with 6.7 percent, or 110 cases, followed by embezzlement with 5.2 percent, or 85 cases, and property damage with 2.4 percent, or 40 cases.

Among the 157 cases where the age of the suspects was identified, 57.3 percent, or 90 cases, were committed by adolescents, while 16.6 percent were committed by suspects in their 20s, the report said.

"Most of the thefts here involve small amounts of money, ranging from a few thousand won to tens of thousands of won, but when accumulated, it is a huge financial loss to owners," said Chae, a man in his 40s who runs a 24-hour self-service ice cream store in Seodaemun-gu, Seoul. He said he has placed warning messages in the store to prevent shoplifting.

Self-service shops, from convenience stores to cafes, rapidly expanded throughout the country as part of the contactless consumption trend sparked by the outbreak of the COVID-19 pandemic in 2020. As of January last year, there were 2,855 staffless shops in Seoul, up 591 from a year earlier.