Police on Monday arrested a 19-year-old temporary worker on suspicion of robbing and killing a taxi driver in Inami, Hyogo Prefecture, in late December.
The temp, whose name is being withheld because he is a minor, has admitted to the allegation, saying he "wanted money," the police alleged.
Police don't believe he was involved in two other attacks on taxi drivers in neighboring Osaka Prefecture.
A senior Hyogo Prefectural Police official said those incidents took place far from Inami and differed in the way they were carried out.
According to investigations, the suspect called for a taxi by phone at around 3 a.m. Dec. 29 and got into Saburo Nagata's taxi near JR Tsuchiyama Station in Hyogo Prefecture.
About 15 minutes later, he stabbed Nagata in the neck and stole his fares in a parking lot about 2 km from the station.
The suspect lives in the city of Kakogawa, which is located next to Inami.
A series of taxi holdups have occurred in western Japan since late last year, including incidents in which suspects have already been caught.
On Dec. 29, a 67-year-old taxi driver was stabbed to death in Higashiosaka, while on Jan. 5, a 61-year-driver sustained serious injuries in Matsubara, both in Osaka Prefecture.
The police believe these two attacks were committed by the same person.