A female caregiver for children was stabbed to death at the apartment in Tokyo’s Suginami Ward. (Video footage by Kenji Notsu)

Photo/Illutration Yusuke Matsuoka is under arrest on suspicion of killing his colleague, Tsugumi Terui. (Hiroyuki Yamamoto)

Police arrested a male children's caregiver on March 30 on suspicion of killing a 32-year-old female co-worker at her apartment in Tokyo’s Suginami Ward.

Yusuke Matsuoka, 31, who also lives in the same ward, has denied the allegation, police said on March 31.

Matsuoka was arrested on suspicion of stabbing Tsugumi Terui in the left shoulder and killing her in her second-floor apartment on March 26, according to police.

Terui was found wearing her coat with a knife, which came from her room in the apartment, sticking out of her back. She died from a loss of blood.

Matsuoka emerged as a suspect based on DNA analysis, witness information and footage from nearby security cameras. Police had been voluntarily questioning him from the morning of March 30.

On the same day, police searched Matsuoka’s home and confiscated a dark knee-length coat, similar to which a man who was seen right after the attack occurred was wearing.

Matsuoka took the day off from work on March 25 and the next day, when the slaying occurred. He came to the office as scheduled on the evening of March 27. A staffer at the children's caregiving home where Matsuoka worked contacted police, saying “There is an employee who is acting strangely.”

The attack was reported to police when the owner of Terui’s apartment, 71, who lives on site, heard screams and a loud commotion around noon on March 26.

Police believe that Matsuoka broke the balcony window of Terui’s apartment, entered it during her absence and killed her after she returned home from work.