A Japanese court on Monday sentenced a 30-year-old man to a prison term of 18 years in a retrial over a 2017 road rage incident that resulted in the deaths of a couple and injuries to their two daughters.

The Yokohama District Court convicted Kazuho Ishibashi of dangerous driving after he overtook the car of Yoshihisa Hagiyama, 45, and his family on the Tomei Expressway in Kanagawa Prefecture, near Tokyo, on June 5, 2017, and forced it to stop in the passing lane where it was rear-ended by a truck.

The court recognized that Ishibashi's actions constituted dangerous driving, which was the main focus of the trial, and described them as "relentless criminal acts based on a strong intent."

Photo shows a minivan removed from a highway in Japan after being rear-ended by a truck in a road-rage accident in June 2017. (Kyodo)

The prison term was handed down by Presiding Judge Kiyoshi Aonuma as sought by prosecutors, who argued Ishibashi was liable for dangerous driving for repeatedly slowing down in front of the family's car. His defense had said there was no causal link between his driving and the accident.

But Aonuma, in handing down the ruling, rejected the argument, saying, "There was a causal relationship."

The judge said the defendant had advanced directly in front of Hagiyama's car four times and repeatedly engaged in obstructive driving by slowing down and approaching the vehicle. Ishibashi's dangerous driving led Hagiyama to take the risky action of stopping the car on a highway.

According to the ruling, Ishibashi was enraged after being warned by Hagiyama about the way he had parked his car in an expressway parking area just before the incident. Ishibashi pursued Hagiyama, who was traveling with his 39-year-old wife Yuka and their two daughters.

The defense side plans to appeal the ruling. Ishibashi was quoted by his lawyer as saying the verdict "did not make sense and that the (court) did not understand the evidence."

The court had convicted Ishibashi of dangerous driving in relation to the case in December 2018, handing him an 18-year prison sentence. Ishibashi pleaded not guilty in both trials.

In the first trial at the same district court, Ishibashi largely acknowledged the facts about his dangerous driving and apologized to the bereaved family. But in the retrial, he maintained he had "not driven in a dangerous way that could cause an accident," and offered no words of apology or remorse.

In December 2019, the Tokyo High Court agreed with the lower court decision but quashed the ruling and sent the case back, stating the district court illegally overturned a view expressed in a pre-trial hearing that Ishibashi's actions did not constitute dangerous driving.

Extensive news coverage of the incident sparked greater public concern over dangerous driving. In 2020, the government enforced revisions to Japan's traffic laws that toughened punishment for road rage offenses.

Ishibashi has also been indicted over a separate road rage incident in Yamaguchi Prefecture in western Japan.

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Nat'l Police Agency mulls revoking driver's licenses over road rage

Mother of road-rage victim calls for harsher penalties