Taipei: Police are actively tracing the finances of Chang Wen to determine how he obtained the money to plan and carry out a recent stabbing spree in Taipei, the head of the city's Criminal Investigation Division said Monday. The attack resulted in the deaths of four people, including Chang, and left at least 11 others injured.

According to Focus Taiwan, Chang, who fell to his death from the roof of a six-story department store while being pursued by police, is believed to have meticulously planned the attack. He began buying supplies more than a year and a half ago, raising concerns about how he financed the attack. Chang, a former professional soldier, was discharged from the military in 2022 for drunk driving and had worked as a security guard for about a year. Following that, he remained unemployed, and in July, a warrant was issued for his arrest after he failed to report for reservist training.

It has been reported that Chang's mother sent him quarterly remittances of NT$30,000 (US$951) last year. Police will report any progress as soon as details become available, Lu Chun-hung said at a news conference on the deadly incident. Lu also urged the public not to spread threats or violent messages online, emphasizing that police will thoroughly investigate such activity to prevent potential copycat attacks.

Meanwhile, the city's law enforcement agency has faced public criticism over its response to the incident. Some have questioned the speed of the police's actions during the attack. During a news conference, the Taipei Police Department explained that the attacker changed disguises five times and used three modes of transport-walking, scooter, and YouBike-which greatly hindered the police investigation.

Chang had scouted the area in advance to familiarize himself with the layout, enabling him to commit the attacks and flee quickly. The police stated they will accept public feedback and review how to better coordinate between agencies and respond more quickly to future incidents.