Ilnaz Rinatovich Galyaviev (born 11 September 2001) was a resident of Kazan, in the Republic of Tatarstan, Russia. He previously attended Gymnasium No. 175 in Kazan and graduated from the school in 2017. After leaving the gymnasium, he enrolled at the College of TISBI (a management academy in Kazan) as an Information Technology student, but he was expelled in April 2021 after failing to attend an exam. At the time of the attack, he was 19 years old and had no publicly documented prior criminal record.

Investigators reported that he had repeatedly sought medical help for severe headaches and that he received a diagnosis of encephalopathy in 2020. In public reporting about his behaviour before the attack, some individuals described him as withdrawn and unsociable, while also stating that he sometimes helped peers academically. Relatives reportedly noticed increased aggression prior to the shooting, while he later denied having serious illnesses during court proceedings, according to reports cited in the case summary.

In the months before the attack, he completed firearms safety requirements and obtained the documents needed to apply for a gun licence. Public reporting also stated that he received a permit and legally acquired a Hatsan Escort PS semi-automatic shotgun in the weeks before the shooting.

On 11 May 2021, a school shooting occurred at Gymnasium No. 175 in Kazan, Tatarstan, Russia. The attack began in the morning at approximately 9:24 a.m. local time. The school had hundreds of students and staff present. As he attempted to enter, he encountered an access control system at the main entrance. During the initial confrontation, a school worker was shot and was able to trigger an alarm shortly after, prompting an internal lockdown response in which teachers secured classrooms.

After entering the building, the attacker moved through corridors and attempted to access multiple rooms while firing at people in the halls. During the incident, an improvised explosive device was detonated inside the school. He also moved between floors, reloaded during the attack, and continued shooting. At one point, he fired from a classroom window toward students outside, causing additional injuries. Investigators later estimated that roughly around 30 shots were fired during the attack.

Seven eighth-grade students and two teachers were killed. Twenty-three others were injured. Reports described emergency response actions including evacuation and medical transport for some of the wounded. Video footage from inside and outside the school also circulated publicly after the attack.

Galyaviev was detained on the day of the attack and, the following day, pleaded guilty to charges relating to the murder of two or more persons. His case proceeded to trial in November 2022. On 13 April 2023, a Russian court sentenced him to life imprisonment. An appeals court later upheld the life sentence in August 2023.