Photo/IllutrationThe site where a male university student was knocked off his bike and killed in an apparent road rage case in Sakai, Osaka Prefecture (Takuji Hosomi)

SAKAI, Osaka Prefecture--A road rage incident led to the arrest of a man on suspicion of murder after his own dashcam showed him aggressively tailgating a motorcyclist before knocking him off his bike.

Security guard Akihiro Nakamura, 40, of Sakai, is also accused of violating the Road Traffic Law for fleeing the scene, police here said July 4.

Police said they suspect that Nakamura intentionally collided with the motorbike ridden by Takumi Takada, a 22-year-old male university student, also from Sakai, on a public road here around 7:35 p.m. on July 2.

“I knew there was a bike in front of me, but I bumped into it,” Nakamura was quoted as telling police. He denies intentionally causing the accident.

Police initially arrested Nakamura on July 2 on suspicion of negligent driving resulting in injuries, but upgraded to murder the following day after watching the footage from Nakamura’s car.

The footage revealed that Nakamura chased the victim for about 1 kilometer for a minute or so while honking and flashing his headlights on the bike repeatedly.

Police believe Nakamura was angered by the victim overtaking him first, and then started tailgating and harassing him.

A fatal road rage case in June 2017 resulted in a married couple being killed on the Tomei Expressway in Kanagawa Prefecture after their car was forced to stop on the passing lane by an infuriated driver, and a large truck crashed into their vehicle.

And last November, a male university student caused a five-vehicle pile-up after dangerously slowing down on another part of the Tomei Expressway in Aichi Prefecture.