Kozo Iizuka (飯塚 幸三, Iizuka Kōzō, IPA: [iizuka koː(d)zoː]; born 1931)^[1] is a Japanese engineer who served as Director of the AIST^[2] and President of the International Measurement Confederation^[3] and Human Frontier Science Program^[3] among other positions. On April 19, 2019, while driving his car, he killed a woman and her child, who were on a bicycle, and injured nine pedestrians in what is called the Higashi-Ikebukuro runaway car crash. Following the crash, perceived special treatment of him by the police, legal system and media, ostensibly due to his privileged position in society, drew much attention and criticism.

He was born in Nakano in Tokyo in 1931.^[4] He graduated from the University of Tokyo. He became a Doctor of Engineering in 1972.^[5]

He was president of the National Institute of Advanced Industrial Science and Technology^[6] and vice-president of Kubota corporation. While vice-president of Kubota, he also served as chairperson of a committee of the Science Council of Japan.^[7]

On April 19, 2019, while driving his Toyota Prius in the Ikebukuro district of Tokyo, Iizuka ran a red light and struck and killed a mother and daughter who were on a bicycle (Mana Matsunaga, 31, and her daughter Riko, 3), injured eight others at a pedestrian crossing, and his wife, who was riding with him. The reported cause of the crash was Iizuka stepping on the accelerator when he meant to apply the brake.^[8][9] About a year before the incident, Iizuka had received treatment on his right knee and was advised by his doctor to drive as little as possible.^[10]

In spite of Iizuka having caused a fatal crash, he was not arrested. Police stated that this was because Iizuka was injured at the scene and was elderly, and hence was not expected to run away or attempt to destroy evidence.^[11] However, in similar crashes caused by elderly drivers that have occurred in Japan following Iizuka's, each and every suspect has been arrested almost immediately, regardless of their age and state of health. This has led to widespread scrutiny and criticism of the police in Japan in regard to just how impartially they enforce the law.^[12]

One of the victim's parents started a campaign demanding that police prosecute Iizuka in line with normal practice and 390,000 signatures were collected. The petition was submitted to the National Police Agency of Japan.^[13] Finally, on November 12, 2019, the Traffic Investigation Division of the Tokyo Metropolitan Police Department referred Iizuka to prosecutors on suspicion of causing fatal injury by negligent driving. Iizuka claimed that there was a mechanical problem with the brake and/or accelerator, but vehicle function tests revealed no mechanical defects. The Metropolitan Police Department concluded that negligent driving by Iizuka was the cause of the crash.^[14] In February 2020, he was prosecuted.

Following the crash, Iizuka is reported to have explained that he was hurrying in his car to a French restaurant where he had made a lunch reservation, concerned that he and his wife would be late.^[15]

Hearings began on 8 October 2020, in which Iizuka continued to deny the charges, claiming that the car had malfunctioned, and saying that he had no memory of accelerating the car.^[16][17][18] On 4 March 2021, a 25 year veteran engineer from the car's manufacturer testified that they found no problems with the car's parts, but the defendant continued to profess that it was a malfunction.^[19][20][21] Iizuka continued to insist that he did nothing wrong at the trial on June 21, 2021.^[22]

Iizuka's closing statement at the trial was that he "did not remember mistaking the accelerator for the brakes". The prosecution asked for seven years of incarceration at the sentencing hearing on July 15, 2021, the maximum allowed for the charge of manslaughter caused by negligent driving.

Iizuka was sentenced to 5 years imprisonment on 2 September 2021 by the Tokyo Regional Court.^[23] Neither Iizuka nor the prosecutors appealed the sentence by the deadline of September 17, so the sentence was confirmed.^[24] The husband/father of the woman and girl killed by Iizuka, Takuya Matsunaga, commented saying that while it does not feel sufficient given how Iizuka spent the last two years making nonsensical claims, it is the maximum allowed, and that he is thankful to the prosecution for it.^[25]

Iizuka's 2015 medal, the Order of the Sacred Treasure for Administrative Services in International Trade and Industry, was revoked after he accepted a sentence of five years in prison.^[26][27]

• Higashi-Ikebukuro runaway car crash