”I don't know why I got angry” - The words of a man in his 30s who suddenly killed a convenience store clerk in South Korea

A man in his 30s who repeatedly murdered female convenience store clerks with his stepbrother, who lived in the same house and had no regular contact with him, reportedly stated that he was "so angry that I committed the crimes."
On the 19th, Gyeonggi Siheung Police Station is planning to send suspect A (35), who was arrested on suspicion of murder, to the Suwon District Prosecutors' Office Ansan Branch tomorrow (20th).
Suspect A is accused of using a deadly weapon to kill his stepbrother B, who lived with him at a residence in Siheung City, at around 6:50 pm on the 12th of this month.
He is also suspected of injuring his mother, who was also a victim of the crime. After the crime, suspect A is also suspected of going to a convenience store two minutes away on foot and stabbing a female store employee in her 20s, Ms. C, several times with a weapon, killing her.
There were two customers inside the convenience store, but the crime by suspect A took place over the course of just four to five minutes. Mr. C was taken to the hospital in a state of cardiac arrest, but died the following afternoon.
Police were dispatched to the scene after receiving a report from a resident and arrested suspect A, who was wandering the road, at around 7:55 p.m. on the same day.
Suspect A told police, "I was so angry that I committed the crime," but added, "I don't know why I was so angry."
" He was reported to have said that he "didn't remember well" the process of the crime. Police investigations revealed that suspect A did not have a particularly bad relationship with B.
It was confirmed that A did not know C either. The convenience store where C worked was not a store that A regularly frequented.
Residents in the area said, "It's such a shame that Mr. C, who had been working there for about three years, suddenly became a victim."
At the entrance to the convenience store, letters, chrysanthemum flowers, sweets, etc. were left as offerings. Police say that after being diagnosed with a mental illness in April last year and being hospitalized for treatment, suspect A was released from the hospital and took the medicine he had been taking for about a month.
It is believed that the symptoms worsened when the patients decided to discontinue treatment at their own discretion.