The suspect in last week's fatal stabbing rampage in Seoul said, "I am sorry," as he was transferred to the prosecution Friday for further investigation and indictment.

Cho Seon, 33, made the remark amid a barrage of questions from reporters as he was escorted out of the Seoul Gwanak Police Station on his way to the Seoul Central District Prosecutors Office.

The police referred him to the prosecution on four charges, including murder and attempted murder.

"I am sorry," Cho said after emerging from the police station without making any other remarks.

Cho was formally arrested Sunday after going on a stabbing rampage near Sillim Station in southwestern Seoul two days earlier. A man in his 20s was stabbed to death, while three others were wounded in the random attack.

He has told the press that "extreme hardship" drove him to commit the crime, while the police quoted him as saying that he "wanted to make other people miserable" because his life was miserable.

He has also reportedly told the police that he had been harboring a desire to commit murder and had searched the internet for information on methods of murder, vital points and knives used in murders.

The police suspect Cho premeditated his crime. (Yonhap)