Police on Thursday arrested a 30-year-old man who is charged with murdering a couple in a city near Tokyo where six people were found dead in three homes in September.

Vayron Jonathan Nakada Ludena from Peru is suspected of fatally stabbing Minoru Tasaki, 55, and his wife Misae, 53, on Sept. 14 at their home in Kumagaya, Saitama Prefecture, the police said. He has denied it.

Investigative sources have said DNA found at the home matches that of the suspect. He is also believed to have smeared a message in blood on a wall there.

The police are also investigating his involvement in the murders of Miwako Kato, 41, and her two daughters, and Kazuyo Shiraishi, 84, given the similarity of footprints found at all three murder sites, which are located close to each other.

The police had not served an arrest warrant as Nakada remained unconscious in hospital after plunging from a second-floor window at Kato's house on Sept. 16. He regained consciousness on Sept. 24.

He has since recovered well enough to walk unaided and have meals, and has been cooperating with the investigation through an interpreter, according to the police. He was discharged from hospital on Thursday and transferred to Kumagaya Police Station for detention.