A 43-year-old man who was arrested for attempted murder in connection with a double stabbing at a McDonald’s outlet in Fukuoka Prefecture in December is expected to be rearrested on a new charge of murder later Thursday, according to police.

Authorities plan to rearrest 43-year-old Masanori Hirabaru, who is currently in custody for the attempted murder of a 15-year-old boy in the fast-food restaurant in the city of Kitakyushu, on a charge of killing Saya Nakashima, also 15.

Hirabaru admitted to “targeting the two teens,” but his specific motives and connection to the victims remain unclear, police said. Investigators also noted inconsistencies in his account of the incident, which further complicate the case.