Police yesterday arrested a 22-year-old man as a suspect in what is now a murder investigation into the disappearance of a Japanese visitor staying on the North Shore.

Masumi Watanabe, 21, 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. That prompted police to reclassify the missing-person case to a homicide.

"We feel that Ms. Watanabe has been murdered," Police Chief Boisse Correa told local and Japanese reporters at a news conference last night. "No family should be put through this."

The chief said it was the first case he can recall in which a visitor was abducted and murdered. Correa said police have told Watanabe's parents — who came to Hawai'i following the disappearance — of their belief that their daughter was killed.

Correa, flanked by Criminal Investigation Division Maj. Alan Fujimoto, Violent Crimes Division Capt. Janet Crotteau and homicide investigations supervisor Lt. Bill Kato, announced that police were reclassifying the case to a homicide based on forensic evidence. He declined to provide details about the evidence but said police have impounded Lankford's business and personal trucks.

Lankford works for Hauoli Pest Control, Crotteau said in response to a question. Lankford was arrested in Kalihi at 5 p.m. yesterday without incident, Correa said.

Calls to Hauoli Pest Control were not returned yesterday.

"We have enough probable cause," Correa said of the arrest. "I'm confident enough that we can move forward."

Police have 48 hours, or until about 5 p.m. tomorrow, to present a case to prosecutors for charges, or would have to release Lankford. Police continue to search for Watanabe.

The Japanese Consulate in Honolulu did not return a phone call seeking comment.

Police earlier said they obtained a search warrant after several witnesses placed Lankford's personal truck in the area where Watanabe disappeared. She had been staying with the host family since February.

Searches by police and DLNR enforcement officers recently shifted from the North Shore to an area near Kahana Bay.

Last Friday, police released photos of Lankford's white 2003 Ford F-150 four-door pickup truck with a silver gas cap near the left rear tire, seeking information from the public.

Reach Peter Boylan at pboylan@honoluluadvertiser.com and Rod Ohira at rohira@honoluluadvertiser.com.