The case of a missing 21-year-old Japanese national, Masumi Watanabe, has been classified as a homicide. Handout photo

Police arrested a 22-year-old man as a suspect in what is now a murder investigation.

"It's a terrible tragedy," said Makoto Hinei, noting that the consulate is in daily contact with Watanabe's parents.

"They are terribly grieved by the news released yesterday by the chief of police. They took the news as only parents do."

Hinei said the consulate was complying with the Watanabe family's request to not release information about Masumi Watanabe, including where she is from in Japan and details about her life here.

Watanabe's parents have been meeting with a Honolulu police officer who speaks Japanese fluently and are grateful for the courtesy provided by the department, Hinei said.

Watanabe, a Japanese visitor staying on the North Shore, was last seen April 12 and was reported missing by her host family when she did not return from her daily walk on Pupukea Road.

Police said blood and items possibly belonging to Watanabe were found in a pickup truck belonging to Kirk Lankford that was impounded last week. Lankford was arrested yesterday in connection to the case, which was reclassified from missing-person to a homicide.